Commercial, freely distributed and "homegrown" real-time operating systems: the mythology of efficiency. Current state of free software Which operating system is free?

Most likely, you have Windows installed on your computer. This operating system may seem free, but it is not. Manufacturers must pay Microsoft a license to supply Windows computers, and you need to buy a copy if you want to install Windows yourself.

There are many operating systems that are actually free. Most of them are quite famous. The most popular is Linux, and if you regularly read news about computer technology, this name is unlikely to be unfamiliar to you. Keep reading this article and by the time you get to the end of this list, Linux will seem completely ordinary. Here are ten other free operating systems that most of us have never heard of.

1. FreeBSD

If you are using a free operating system that is not Linux, then it is probably based on BSD. FreeBSD is just one of several UNIX-like operating systems. Others include NetBSD, OpenBSD and PC-BSD. Whichever you use, most of the experience is similar to what you'll find on Linux. Free and open source software that is available to one person can usually run on another.

Even if you are not a fan of free software, you may be using parts of FreeBSD without realizing it. Due to the project's permissive license, some of the code made its way into Apple macOS, Sony PlayStation 4 and Juniper routers.

2. ReactOS

Most free operating systems are alternative to Windows. ReactOS, in a sense, strives to be Windows. The goal is to provide users with the means to run Windows software without having to purchase the operating system from Microsoft.

ReactOS is a free and open source operating system, so it cannot use any real Windows code. The project has partially implemented many of the Windows APIs, and it collaborates with the Wine project to run programs, applications, and software.

3.FreeDOS

Have you used computers when DOS was the only option? Do you have good memories of MS-DOS?

FreeDOS allows you to relive this bygone era. OS barebones gives you a means to run older DOS programs on more modern hardware or within virtual machine. Or you can just use it to run older games.

4. Haiku (Haiku or Hokku)

Haiku takes inspiration from BeOS. BeOS was a graphical operating system developed by Be Inc to run on the BeBox back in 1995. The operating system was stuck for five years before latest update came out in 2000.

BeOS may not have been a household name, but it attracted some users, and some wanted the operating system to live long enough to create their own open source version. The goal is for software written for BeOS to run on Haiku, similar to what ReactOS wants to do on Windows. All things considered, the haiku team may have an easier time of it.

5. Illumos

Oracle is used to support an operating system called Solaris. It was initially closed, but the project was opened in 2008. Oracle discontinued OpenSolaris in 2010 and returned to its own model with Solaris 11 in 2011.

6. Syllable

Syllable is based on AtheOS, an AmigaOS clone that was abandoned at the turn of the century. As for AmigaOS, it is still alive despite being born in the 80s for a line of computers long considered ancient.

Syllable is designed for home office users with a user-friendly interface and native applications including a Webkit-based web browser and mail client. The thing is, it can only do this on a computer with 32MB of RAM (although at least 64MB is recommended for viewing). The complete installation should take approximately 250 MB of hard drive space.

7. Research operating system AROS

Although Syllable is based on an AmigaOS clone, AROS takes a different approach. It actually places its binary compatibility with AmigaOS at the API level. This is similar to how ReactOS targets Windows and Haiku targets BeOS.

You might be wondering if AmigaOS is worth all the attention. Did I mention that AmigaOS is still here? It's not free either. Someone out there is still willing to pay for an operating system that most people have never heard of. AROS offers a way to use some AmigaOS programs without having to pay money. Plus, it's open source, which can leave you feeling secure.

8.MenuetOS

That's what MenuetOS is - it's small enough to fit on a single floppy disk. These were flash drives from the 90s and only offered up to 1.44MB of storage. Considering that many Linux distributions struggle with the 700MB CD, booting from a floppy is difficult these days.

MenuetOS is written entirely in 32-bit assembly language and is designed to run with minimal overhead, although it supports up to 32GB of RAM.

9. DexOS

Are all desktop operating systems feel the same? Here's one that takes a different approach. Bringing DexOS to life will feel less like using a computer in keyboard class and more like playing on a mainstream gaming console.

Launching apps in DexOS feels vaguely like inserting a disc into an old Dreamcast. The experience feels more authentic if you actually play the game. And another cool thing? This free OS is also small enough to fit on a floppy disk.

10. Visopsys

Like DexOS, Visopsys is a hobby project of one developer. Install it if you want to see what just one person can create.

Visual Operating System (admittedly this name can be applied to any OS with working environment) has been in development since 1997. It is not based on any pre-existing OS. This does not mean that the project does not use existing code. Here you will find common GNU tools and icons that may be familiar to KDE Plasma users.

Will you use any of these free operating systems?

Most of them are not. Haiku developers do not work full time. Developer Visopsys is clearly saying that their OS is not as capable as Linux or, perhaps a fairer comparison, Syllable. DexOS is more of an experiment than anything else.

However, there are many people who prefer FreeBSD over Linux. illumos may not be well known, even among FOSS enthusiasts, but it has its uses. And didn't I mention using FreeDOS to play all the old DOS games?

Are there systems on this list that you would like to use? Do you know of another unknown free operating system that is not on this list? Let us know about it in the comments!

Let's say that you have a new project brewing, and you choose a software platform for it. Depending on the degree of involvement of third-party intellectual potential, there are four options:

• do without RTOS at all;
• develop an RTOS independently;
• adapt a freely distributed general-purpose OS to your needs;
• use a ready-made commercial RTOS.

Often, due to a lack of information and a lack of understanding of the issue, decisions of this kind are made “on the basis of concepts”, and therefore are subject to a fair degree of prejudice. Let's look at the most popular of them.

Myths...

"Not every application needs an OS." Within reasonable limits (read - for small single projects) this thought can work wonders; however, when taken to the point of absurdity (“why do I need a hammer, I just need to hammer in one nail”), it can do a lot of harm. If the project grows and develops over time (and for an enterprise that is on the market seriously and for a long time, this is the natural order of things), the amount of code that will have to be maintained and modified will very soon grow to such volumes that the size of the costs will put the project’s payback at serious risk. question. At the same time, the costs of transferring a project to another platform are both direct (the cost of the platform itself, the cost of staff training, the cost of work on transferring code, etc.) and indirect (for example, loss of market share due to lagging behind competitors, caused by the time spent on transferring the code) - may be such that the transfer will no longer be able to pay for itself, and good project will be ruined forever.

“Developing your own RTOS is a matter of a couple of months.” This fairly common misconception originates from project management theory: they say that an estimate of the resources required to develop your OS can be obtained by dividing the average cost of a commercial OS of a given class by the cost of an average programmer’s man-hour. Here, however, it should be clearly understood that programming is an iterative process. Remember the joke from the old days: “renovation cannot be completed, it can only be stopped.” It's the same story with software projects. The market situation is constantly changing, and any project is always a “living” project. This means that once you take up development, you will be forced to do it all the time, and the resources allocated for it will never be freed up.

"A commercial RTOS is a complex product that will take a long time to master." This argument comes up quite often, and for this very reason it is, unlike general-purpose operating systems, in most cases inapplicable to commercial RTOSs. Most commercial RTOSs are designed from the outset with this in mind, since their main strategic purpose is to reduce the time to market for new products, including by shortening the learning curve. If the product is difficult to master, no one will simply buy it.

"Commercial RTOS is overloaded with unnecessary functionality." Any universal product always contains some redundancy, which may not be necessary in each specific case. However, embedded environments often simply do not allow resources for redundant software, and developers are forced to adapt. As a consequence, all modern commercial RTOSs are scalable and allow unnecessary functionality to be excluded from the target configuration.

"The RTOS is well known and can therefore be well documented." Documenting a project always has one goal - to make it easier to study. And both for customers and for new participants in the project. However, if the project is being done for internal use, there are always a thousand more important things to do than document something for which there is always a specialist at hand. Developers also readily accept this point of view, since they hate writing documentation. What happens next - see below for more information.

“You can finish your RTOS in a finite amount of time and not think about it anymore.” This issue has already been partially discussed above (see “Developing your own RTOS is a matter of a few weeks”), we just need to add that in programming a very unfavorable factor is “staff turnover”. The market is constantly evolving, requirements for products are changing, and even for the most successful RTOS one day there comes a time when changes need to be made to it. By this point, the specialists who developed it, at best, have already forgotten what they did two years ago, and at worst, they have moved to work for another company. As a result, new version if it comes out, it is with a lot of delay and a lot of errors.

"Using your own or a freely distributed RTOS allows you to save a lot." It should be remembered here that the cost of the project consists not only of the cost of tools and components. IN general case it includes at a minimum:

• cost of tools;
• tuition fees;
• development resources (time, personnel, jobs, support, consulting, etc.);
• cost of components and assembly;
• cost of support.

And here, as elsewhere, the “golden rule of mechanics” works: if you win in one thing, you lose in another. A product is a product, but the importance of a package of related services (training, support, consulting, custom development) as a means of reducing the product’s time to market cannot be denied. There are three options here:

• refuse services altogether;
• order them from the product manufacturer;
• order them from a third-party consulting company.

The first option, obviously, allows you to save money “here and now”, but loses in time and labor costs, because you have to do everything yourself, and no one will help. This is fraught with serious delays, which can be very expensive in a highly competitive market.

The second and third options are very similar and differ only in how much profit their products and services bring to companies. The manufacturing company makes a profit from both its products and services, and in what proportion is an individual question. A consulting company does not produce a product and makes profit only from services, so often the cost of its package of services is comparable, or even exceeds the cost of a commercial product. In other words, if in front of you is a sandwich with free cheese, then there is every reason to assume that either it is a mousetrap, or it makes sense to think about how much the bread costs.

From the above, one simple conclusion follows: none of these approaches is optimal in its essence, and before making a decision it is necessary to analyze all possible options individually in terms of total cost of ownership (TCO), that is, costs over a long period of time.

"What we have is also a real-time OS." Interpretation of the term " real time“depends heavily on the application, and unscrupulous manufacturers often take advantage of this. There are two things you need to know here. Firstly, RTOSes are divided into two classes - “hard” and “soft” real-time operating systems. The first guarantee a clearly defined response time to an event (this the property is ensured by a specially designed OS architecture), the latter, as a rule, manage to process the event within a specified time interval. Accordingly, a “soft” real-time OS is not suitable by definition for implementing a deterministic system (say, a control loop).

Secondly, the time it takes for an RTOS to process an event is not specified in the RTOS definition. In other words, if an RTOS is guaranteed to process an event, say, within 1 day, then formally it can be considered a hard real-time OS. Conclusion: before choosing a tool, you need to clearly understand the requirements of the task at hand. By the way, all hard real-time operating systems that provide response to an event within microseconds are commercial. Which, however, is not surprising: a serious task requires a serious tool.

"A freely distributed OS eliminates copyright issues." But this is not true. Any code is almost always subject to some kind of license; Moreover, these licenses often conflict with each other, as a result of which components that are physically compatible with each other, for example, by law, may not be included in the same distribution. The general rule here is this: any license imposes certain restrictions, and they must be clearly understood, otherwise problems with acceptance may arise. The customer always needs a licensed product - if only because it will clearly indicate who will be responsible if something goes wrong. And no one is responsible for a product that does not belong to anyone.

...and some facts

In addition to the above myths, there are also a number of hard facts related to commercial RTOS; however, they often either remain in the shadows or their importance is underestimated. Let's list some of the most important of them with some comments.

Detailed documentation. Documentation is an integral part of the product. Developers using an RTOS cannot afford to spend a lot of time studying its design, so even the best product loses its value if it does not have high-quality, detailed documentation. In addition, the capacity of technical support services is always limited, and writing documentation is always more profitable than answering the same questions repeatedly. Therefore, commercial RTOSes are always well documented.

Tested code. The number of clients of a commercial RTOS development company can be measured in the hundreds. This means that the code of this RTOS will undergo continuous testing in many places at the same time, in different configurations and modes. No local testing unit can provide such testing efficiency. Accordingly, commercial RTOS always contain fewer errors than “home-grown” ones.

Specialized tools. Real-time applications have certain specifics (for example, the mechanisms for scheduling and synchronizing tasks in an RTOS differ from those in a general-purpose OS), and their debugging requires specialized tools. In this case, a regular debugger is often not enough, and standard means diagnosis is usually not enough. In addition, all modern RTOSes are designed for embedded configurations, so the developer can efficient work What you need is not just a compiler and a debugger, but an integrated line of tools that can take you from writing code to generating and optimizing a ROM image. Only commercial RTOSs have such tools.

Additional components. The operating system itself is not everything. In addition to the basic functionality provided by the operating system, your project may require additional software components - protocol stacks, graphics, database tools, etc. If you develop an RTOS yourself, then be prepared that you will have to develop everything else yourself. This option of porting ready-made components to your own RTOS can be excluded immediately, because this requires that your RTOS fully support a certain universal API (for example, for most freely distributed software this is POSIX), and this is for “home-grown” RTOS often considered an unnecessary extravagance.

Professional services. And, perhaps, the last thing - as they say, in number, but not in importance. Even the highest quality and detailed documentation does not solve all problems - if only because the textbook must always be read in full, and you must be able to search in the reference book. Both can take a very long time for a complex product because the amount of documentation is often very large. If you encounter a problem, then you most likely need to solve it quickly, and only someone who knows the system “from the inside” - its developer - can help you with this. In this sense, freely distributed RTOS do not provide any guarantee, because by not answering a question in a public forum, no one is risking their reputation, which means there can be no confidence that you will quickly receive an answer to any question. It remains to compare the annual cost of maintaining a staff of developers with the cost of an annual technical support plan for a commercial RTOS. In most cases, the last option wins. In addition to this, as already mentioned, typically the professional service packages provided by commercial RTOS manufacturers are not limited to technical support and also include staff training, custom development, certification, project consulting, etc. - in a word, everything that helps to complete the project competently and on time.

Resume

Choosing a tool for serious work, especially in a highly competitive environment, is always a key point. A tool is a thing that is chosen seriously and for a long time; however, we have to admit that there are no universal tools. Each task has its own optimal tool, and the right decision can only be made by knowing the requirements of the task at hand, as well as its background and prospects.

There are no miracles in technology; they are all nothing more than unconscious patterns. Therefore, any goal must be measurable, otherwise it will be impossible to assess whether it has been achieved or not. Likewise, any characteristic must be measurable, otherwise it will be impossible to compare what is offered with what is required. The only thing that should guide you when choosing a software platform for a project is your goals and the extent to which the platform's characteristics match the project's requirements. And myths, no matter how plausible they may look, can only provide mythical effectiveness.

Nikolay Gorbunov

SWD Software Ltd.

Many
users by the words “free” and “open source software” mean
GNU/Linux operating system. But there are several dozen
free OS, among which there are both successful and popular products
(FreeBSD, Solaris, Darwin), and known to narrow circles of specialists
projects (Haiku OS, React OS). Each of them has its own history and future.

There are several dozen free operating systems in the world, and some
Every IT specialist needs to know them. Most famous after Linux
operating system - BSD. It was developed in 1978 in
Berkeley University based on UNIX OS. Of the most common
distributions of this open system can be called FreeBSD, PC-BSD and
DesktopBSD.

In force technical features UNIX, fragments and variations of this OS
widely used in various equipment, most often in network equipment. Servers on
based on FreeBSD they are highly stable and also actively
apply. Desktop versions of BSD use the KDE graphical shell
and outwardly practically indistinguishable from Linux. Moreover, these systems
received native support for software created for Linux.

BSD is the most famous free operating system after Linux.

Another offshoot of UNIX is the operating system from Sun
Microsystems called Solaris, created in 1991. Free
the company's supported version of this OS is Open Solaris. Despite
the presence of certain features inherent in GNU/Linux (graphical
Gnome user interface, installing software packages from
repositories, native Linux ABI support, booting the system from LiveCD),
this OS is designed for use as a development platform
for Sun Microsystems server products. The fundamental difference from
Linux is the core of the system. Early versions of Sun Microsystems OS
used Unix and was called SunOS.

Open Solaris has similarities in appearance to Linux

In 1992, SunOS 5 was renamed Solaris 2 in its release.
additional proprietary components appeared in the distribution. According to this
For the same reason, OpenSolaris is no longer distributed under the GPL, but under the CDDL
license, which presupposes the presence in the distribution of files licensed
according to other principles, including proprietary ones.

The most famous free operating systems after Linux

In the late 1980s - first half of the 1990s in the development of Unix systems
Another stage has begun related to the release of NEXTSTEP OS. At the heart of this
The proprietary system contained the Mach kernel with Unix source code.
After the actual cessation of development of this OS in 1995 and after
purchase of NeXT by Apple, almost all its main components
(user interface, OpenStep/Mach and system libraries) were
used in Rhapsody OS, the successor to the future Mac OS, released in 1998
year. However, in 2000 year Apple stopped developing Rhapsody OS and
began to develop another branch of UNIX and BSD - Darwin.

This operating system is based on the XNU kernel (used
Mach microkernel and standard BSD services). The product is licensed under
APSL, which refers to free software, and its variants are PureDarwin and
OpenDarwin (merged with PureDarwin in 2006) uses the LGPL. From BSD to
the Darwin kernel included a processor model, networking stack, and
virtual file system, plus Apple added
object-oriented API for I/O Kit device drivers. Final
option allows you to compile most Unix applications under Darwin
without interfering with source code.

Free OS for users

UNIX systems and various offshoots differ from them quite
strict focus on use in servers or for development
applications. Use them as a replacement for existing desktop ones
decisions in most cases does not make sense. Besides the absence
support in the basic supply of drivers for multimedia devices, a number
media formats, tools for customizing user
interface, these systems are difficult for the average user to understand,
despite the fact that they often have the same shells as
Linux distributions (KDE, GNOME and other X-Windows variants).

How is Linux different from other freeOS?

Despite certain similarities between Linux and other free
OS, there are several major differences between them. First and foremost
main thing: Linux uses the Linux kernel, which is different from Unix and
Unix-based systems both in their architecture and principles
licensing (GPL). The second difference: the use of the X Window System, on
based on which the graphical user interface is built
most Linux distributions. In free operating systems they are more often used
own interface development. The third difference is the use
utilities and libraries from the GNU Project on Linux.

But there are open source OSes for desktops as well. Pioneers in this
direction was the company Be, which released in the early 1990s
proprietary BeOS, as well as BeBox computers. Developers
positioned it as a competitor to Windows and Mac OS, primarily in terms of
the reason for adapting the system to solving multimedia problems. Nevertheless,
active development of this development ceased in the early 2000s
years in connection with the purchase of Be Palm. The only open-source
a variant of BeOS is Haiku OS, which is a port of
kernel, API and file system from BeOS with open source software distributions, for example,
Firefox, VLC, SeaMonkey. Unlike Linux, it does not use
X-Windows graphical shell, different system of ports and libraries
(however, since the end of January 2009 the situation began to change, and in HaikuOS
now you can run modern programs, like Firefox 3).
It is noteworthy that this OS is still in a state of deep
development, and the timing of its second technical release is still unclear.

HaikuOS can't get out of deep development state

Another project similar to Haiku OS is Syllable OS, an existing
in the form of two distributions - a server based on Linux kernel, And
desktop, using our own development. By and large, in
Syllable programmers decided to connect best practices open
source systems, borrowing the GCC compiler and subsystem from GNU/Linux
SDL, as well as interface elements from BeOS and applied POSIX standards,
known from UNIX systems. However, support work
Most modern equipment in Haiku OS is extremely
slowly, which affects the availability of release versions.

Minimum non-standard

Another little-known representative of free operating systems is
real-time operating systems (RTOS). Among similar projects
we can highlight pico]Os (BSD license), eCos (own license for
based on GPL) and FreeRTOS (modified GPL). Listed
operating systems are used in devices in which to use
Linux or BSD is not practical. RTOS are not technically demanding
device capabilities and are actively used in terminal clients,
in BIOS, in video surveillance and control systems, in industrial
equipment.

And again Windows

However, in the camp of open source software supporters there was also the presence of
fans Microsoft Windows. It is known that many system
architects and programmers still consider it the most successful version
Windows 2000.

ReactOS developers share a similar opinion. The basis here
Windows API was taken, and additional proprietary ones were removed from the distribution
tools and software (what remains is licensed under GPL/LGPL).

Types of licenses used in free operating systems

It is assumed that the user will download the necessary
him components after installing the system. Another open source
developed based on Microsoft products is a well-known system
FreeDOS, which can often be found as a pre-installed OS
on Dell laptops and HP. At the heart of this GPL-licensed system
lies a kernel similar in functionality to MS-DOS, a command interpreter
lines, as well as a set of additional utilities and drivers (in particular,
FreeDOS runs on NTFS, unlike MS-DOS).

ReactOS - free analogue Windows supports the same drivers and programs.

List of operating systems discussed in the material, this class of software
provision is not completely exhausted. There is still enough
the number of different amateur projects being developed both for
own account by enthusiasts (Menuet OS, Kolibri OS and others), and
financed by companies (for example, various options Plan 9 by Bell
Labs). In addition, a number of projects are in a “frozen” state, and
their creators do not release new versions of existing developments or
prototypes have not yet been made publicly available.

Mikhail Demidov

We present to your attention a selection of the 10 best operating systems that are perfect for both everyday work and for finding new features for your PC.

Despite the widespread use of different Windows versions, every year more and more users begin to look for new interesting OS.

Installing a new system on your computer allows you to work with programs that do not run on Windows. Some users prefer to use other operating systems to ensure the security of their data. Also, simple and lightweight OS options significantly speed up the operation of old laptops and help get rid of the problem of constant overheating and slowdowns.

10th place – Windows 10

Despite the fact that in this rating we abstract from the huge number of versions of the well-known Windows, we cannot help but highlight one of the most successful and fast versions– Windows 10. Don’t be surprised that we put Windows in 10th place. Yes, it is the most popular, but precisely because of this, it is one of the most hackable and not always safe. And it also costs money, unless, of course, you downloaded its distribution from pirated sites.

The system is very simple to use and will appeal to both fans of the metro interface and those who are accustomed to the regular Start menu. The official assembly has everything necessary programs to get started, including a new one fast browser MS Edge.

Windows 10 benefits:

• The START key has been returned. In the eighth version of the OS, the developers relied on a tiled interface, which did not delight users. Now the PC owner can independently choose how it is more convenient for him to work with the start screen;
• Windows 10 is Microsoft's latest development. This means that all the company’s efforts are aimed specifically at improving and maintaining the operation of the OS. Security update packages are released almost every week. Microsoft also performs well in quickly eliminating viruses. Owners of computers with licensed tens have repeatedly noted that they managed to avoid the massive spread of malware thanks to quick developer updates;
• Availability voice assistant Cortana. With the built-in speech recognition service, working with search will be even easier;
• Reliable Firewall. With built-in Microsoft Defender, there is no need to install additional antivirus programs. The firewall does an excellent job of detecting threats and quickly blocks execution malicious code, allows you to scan the system;
• Quick start. The operating system starts in less than 15 seconds, regardless of your PC's performance;
• Setting up multiple desktops. Users can add an unlimited number of home screens and easily switch between them using hotkeys.

It is worth noting that Windows supports almost any games and programs, so there will definitely not be any problems installing the software.

Disadvantages of Windows 10:

• User tracking. Microsoft does not hide that new Windows 10 is capable of tracking user actions. The system regularly scans your PC for the use of illegal software products from Microsoft. Now the hacked one will simply be deleted from the PC. It is also no secret that the OS sends the developer data about visited resources and desktop photos. If desired, all these options and permissions can be disabled in the settings;
• Usage Policy. Even after a long time since the release, the developers still have not decided on a distribution policy. In the first year the owners Windows licenses 7/8 could upgrade to ten for free. Today it costs money (from 8,000 to 14,000 rubles, depending on the assembly). At the same time, a loophole has been found that allows you to update for free using the built-in Accessibility utility.

9th place – ROSA

ROSA is a Russian build of the open Linux OS. The standard kernel of the operating system was completely rewritten by the developers of the ROSA company. The goal of the project is to create a functional, free and convenient system that will suit any Russian-speaking user.

ROSA OS completely free system. There are no purchases within the OS itself either. The availability of the distribution contributed to the spread of the system not only among ordinary users, but also among large companies. As you know, ROSA is used both in units of the Ministry of Defense of the Russian Federation and in many private companies throughout the country.

Advantages of ROSA OS:

• Everything is ready to go. After installing the system, you do not need to install any drivers and additional programs. Everything you need is already in the system. If you wish, you can download the software from any specialized site. As you know, Linux has almost zero percentage of virus programs, so installation from third-party sources does not pose any danger;
• Test mode. For those who have not yet decided to completely switch to ROSA OS, the developers have provided a guest mode. You can create a regular installation flash drive and boot from it. The OS will not be installed, but the user will be able to get acquainted with its interface and functionality;
• User-friendly interface. The arrangement of all elements is very thoughtful. Even a beginner can master the new system in 10-15 minutes. All programs are conveniently divided into tabs on the desktop. You can pin frequently used programs to the Toolbox. The start screen is reminiscent of Windows functionality;
• Virus protection. The risk of downloading malware is minimal, so you can browse any sites and install programs and games without any problems. If they have a virus embedded in them, then it will only work in Windows or other more common operating systems.

Among the disadvantages of ROSA OS, one can highlight a small number of programs. Not all Windows software has analogues for the Linux kernel.

8th place – FreeBSD

FreeBSD is an operating system that is designed to work with servers, and now regular desktop PCs. More than 30 years have passed since the first development of this system began. Today FreeBSD is a simple, reliable and convenient OS that will be a good replacement for the usual Windows.

Benefits of FreeBSD:

• Free license and download from the network;
• Open source code allows you to modify the system;
• Spreading. FreeBSD is used by many popular sites in the world to maintain the server part - Webmoney, Aliexpress, ASOS and others;
• Protection and reliability. It is worth noting the well-thought-out OS logic and rational consumption of PC resources. FreeBSD runs fast even on low-end computers;
• Large selection of software. More than 4 thousand developers from all over the world are developing versions of programs for FreeBSD. Thanks to this, current versions all popular programs quickly appear in the public domain.

Disadvantages of FreeBSD:

• Difficulty setting up. This is exactly what it is main reason FreeBSD's low popularity among ordinary users. Once you've figured out the first OS setup, you'll have a system that runs much faster than Windows;
• Difficulty obtaining documentation. If you want to set up administration for your FreeBSD site, you'll need to take the time to find the administration documentation.

To ensure security, FreeBSD uses all the necessary levels of protection: encryption mechanisms, authentication control, checking incoming and outgoing traffic, regular monitoring of the system for the presence of malicious code.

7th place – Fedora

Fedora is a Linux-like operating system that features free software. It should be noted that the drivers used may be closed source, and some types of software may have a limited license (for example, codecs for media playback).

Fedora Benefits:

• Using the Gnome environment. Gnome's development for Fedora is considered one of the most successful desktop implementations in operating systems;
• Easy to use. The developers have created a simple and beautiful design for the desktop and program tabs. Quick movement between open applications and folders is possible thanks to the side toolbar;
• Pre-installed programs. After installation, you will have access to a software package to fully start working with Fedora (web browser, explorer, image viewing utility, management software virtual machines and others);
• Quick installation of new applications. Installation of the software occurs through the “Application Center”, in the same way as on a regular smartphone;
• Possibility of over-the-air updates. You can download and install new OS firmware using the Gnome Software utility.

Disadvantages of Fedora:

• Among developers, Fedora is considered a "free ground" for testing programs. All applications appear faster, but there is a high chance that the software will be unfinished and unstable.

6th place – Elementary OS

Elementary OS is a fast and at the same time functional replacement for the usual Windows. The developers position the system as a simple environment for work, which logically follows from the name of the OS.

The system uses the Linux distribution kernel. Elementary OS is distributed free of charge and works on absolutely all computers, regardless of hardware components.

Advantages of Elementary OS:

• Convenient and pleasant interface. The minimalist style is the basis of the operating system functionality. A minimum of elements have been added to the desktop, but all of them allow you to manage the OS without any problems. It should be noted that window switching is smooth and very fast loading programs;
• Easy to learn. Even a novice user can understand Elementary OS. No complex commands, forced work with the console and unclear parameters. The functionality can be compared to the ease of use of the Android mobile OS - all basic settings can be adjusted in the desktop tools window.;

• An excellent set of standard programs. As a rule, users do not take applications pre-installed in the OS seriously. In the case of Elementary OS, the developers tried to create a useful basic software package that you won't want to remove;
• Regular stream of new programs. Developers quickly adapt programs for Elementary OS.

Overall, the system is great for home use. Such an OS is still not suitable for administering a server or creating a workstation. Elementary OS security is ensured by built-in Linux protection modules.

If you have a weak computer or want to install an additional “light” OS, feel free to choose Elementary OS.

5th place – Chrome OS

Chrome OS is an open source operating system from Google. The main feature of the system is the use of a hybrid kernel (Linux kernel combined with Google services).

The OS is distributed completely free of charge, and its popularity among users is due to fast work and nice design.

Advantages of Chrome OS:

• The system is dominated by web applications, and the key role in system management is given to Chrome browser. It is with its help that web applications are loaded and run;
• There are no special requirements for hardware architecture. Thanks to the simple concept of Chrome OS, you don't need a powerful PC or laptop to install the system. On the contrary, the system was specially designed for low-performance machines (netbooks, low-end laptops) price category). Using web services can reduce the load on hard drive and RAM;
• Automatic security. Protection module update packages are downloaded regularly. Also, the system has a built-in defender to quickly identify threats;
• Easy to use;
• Availability of software. You can download all programs from Google Play or Android service Nougat. The abundance of software in these online stores will not allow the user to experience a shortage of applications. In addition, all software is perfectly adapted for the desktop operating system.

At first glance, the Chrome OS interface resembles a combination of Android and Windows. Installed programs are placed in a separate menu, and the system is controlled using the toolbar, as in the Windows desktop.

Among the disadvantages of Chrome OS is the need for a constant connection to the Internet. It is advisable to use Wi-Fi network or Ethernet connection. IN otherwise, you will not be able to work with web services.

4th place – OpenSuse

OpenSuse is another popular distribution that runs on the Linux kernel. Used to support both servers and home computers. New system firmware is released regularly; all release dates can be found on the developer’s website.

An OpenSuse user can independently customize the system. You don't need any programming skills to do this. Changing the interface consists of choosing the desktop environment you like. While most Linux builds can only work with one desktop environment, OpenSuse supports multiple styling utilities. The most popular of them are KDE and XFCE.

Benefits of OpenSuse:

• Easy setup. You can manage the operating system using a single YaST application. This tool allows you to adjust OpenSuse operating parameters. Users can independently add repositories, manage boot parameters, OS partitions, network connection settings and other parameters;
• Free distribution of software. OpenSuse will run all the programs you need. The system automatically adapts the software for your computer;
• Easy installation of programs. Unlike most Linux builds, you no longer need to install repositories, add access keys, and carry out complex settings yourself. Just download the desired program from the official source https://software.opensuse.org/ and install in one click.

Disadvantages of OpenSuse:

• The standard build lacks codecs and driver software, which complicates the first OS setup;
• Users note the unstable operation of the standard MonSoon torrent client.

3rd place – Ubuntu

Ubuntu is a universal operating system that runs on the Debian GNU/Linux engine. The system works fine on servers, personal computers and laptops. The standard build comes with a desktop environment running Unity.

Ubuntu benefits:

• Working with equipment. Ubuntu supports a huge number of connected device types. For example, any connected via USB device will work without any problems and driver software;
• User support. Ubuntu OS has the largest and most responsive community. If necessary, beginners will be able to get answers to all questions using the official website of the developer;
• Reliability. The OS has built-in utilities for backup data. The system independently creates copies of important files, archives them and sends them to the cloud. This ensures the reliability of Ubuntu. If you administer a server on this OS, the best way there is no way to quickly roll back data;
• Security system. The developers have provided a whole system of applications that background monitor vulnerabilities. Ubuntu is considered the strongest Linux distribution in terms of security;
• Program Center. Special utility for searching and installing programs also allows a beginner to become familiar with the basics of installing software under Linux. On each application page there is detailed description software, its requirements and reviews from other users.

Ubuntu is distributed free of charge. As for the shortcomings of the system, we can highlight the lack simple means migration from Windows OS. Also, Ubuntu lacks effective utilities for parental controls, so installing the distribution for family use is not recommended.

2nd place – MacOS

MacOS is a family of operating systems from Apple. On at the moment, the most current build is Mac OS Sierra. Unlike the operating systems described above, Mac does not run on Unix-like systems, but using Apple’s native engine.

The system distribution is distributed free of charge.

Advantages of MacOS:

• Usability and graphical shell. This OS is recognized the best system for users. All options and settings are designed for quick learning. The interface is multilingual, intuitive and convenient;
• High degree of protection. Mac OS is the most secure among all modern operating systems. The number of viruses is almost zero, and the built-in antivirus can handle all “pests”;
• Easy to install and remove programs. Simply move the shortcut to the trash can to complete removal applications. Mac OS does everything for the user. You don't need to manually clean your hard drive like you do in Windows or Linux;
• Stable job. Due to the high compatibility of components, users do not encounter bugs, freezes or crashes in the OS.

Disadvantages of MacOS:

• Compatibility. If you are the owner of a regular PC, and not Macintosh computer, you can install an operating system only if it is compatible with the hardware components. MacOS runs on a limited number of processors (mostly Intel Core and Xeon);
• Fewer programs than in Windows.

1st place – Linux Mint

Linux Mint is recognized as the best build for installation on user PCs. It satisfies all the requirements of the average user - it is distributed free of charge, is compatible with any hardware, efficiently consumes PC resources and has a user-friendly interface.

Benefits of Linux Mint:

• Quick start. The system boots in 10-12 seconds, which is significantly faster than Mac OS and most Windows systems;
• Support for working with multiple desktops;
• Built-in utility for quick installation and uninstalling programs. In this version of Linux, users will not have to deal with repositories. Everything is done for convenient work with the software;
• Multilingual interface;
• Quick system debugging. If you encounter programs freezing, you can disable the process by pressing one key;
• Supported by all desktop PCs and laptops.
• User-friendly interface.

Disadvantages of Linux Mint:

• A limited amount of software for specific tasks (video editing, working with graphics, etc.);
• Lack of stable graphics driver for AMD, which may cause some games to not work correctly.

Bottom line

When choosing an operating system, first of all pay attention to the tasks you set for the software environment. Need a fast and secure OS for everyday use? Pay attention to Unix-like systems.

If you want a reliable OS with excellent graphics, we recommend choosing Mac OS. For lovers of interface and functionality mobile systems you should start using Chrome OS.

Freely available UNIX system

A fairly cheap PC and a freely distributed UNIX system make this system accessible to almost everyone today.

Very popular UNIX version for the PC, called Minix, was developed by Andy Tanenbaum as a companion to his book on UNIX architecture. Tenenbaum's book contains complete listings of the system's source code. An additional set of floppy disks allows you to install Minix even on a PC with an 8086 processor (if such a computer is available).

IN lately A freely distributed version of UNIX called Linux, developed by University of Helsinki researcher Linus Torvalds, is becoming increasingly popular. Designed from scratch for Intel processor i386, today it has been ported to a number of other hardware platforms, including DEC's Alpha servers.