What is the best free operating system?

This is impossible to answer conclusively. In addition to the fact that no operating system is perfectly suited to all tasks, the word free itself is up for debate.

Free can have several different meanings to different people. To many people it means that it is free of any monetary cost. To others, free means that something lacks any restrictions on what you can or cannot do with it.

In operating systems, an operating system that restricts what you can do with it (such as modify the code or sell it) is considered proprietary. The only free operating systems that do not impair your rights to sell or modify them. Even within free systems, there is debate. Systems under licenses like the GPL force you to make any changes you make to a program you release to the public freely available. Other licenses like the BSD or MIT license allow you to keep the changes you make proprietary, and even re-license under a different license without making the source available.

Comparison of freeware proprietary operating systems



The operating systems that are considered the best in their field are listed below. More than one will still need to be listed, as there are still things about them that would make them unsuitable for a large number of people.

Desktop / Workstation



MorphOS - MorphOS is a desktop operating system with a multimedia-oriented operating system modeled after AmigaOS. Limitations: available only for workstations with PowerPC processors. Limited selection of applications. No memory protection.

BeOS - Multimedia desktop with many features considered rather advanced in its time. Fast microkernel design. Interface is considered by most to be very easy to learn. Decent homebrew community. Limitations: Company went out of business. Limited selection of apps. Often does not work on computers newer than 2004.

QNX - Fast and responsive on extremely low-end / older hardware. Highly reliable and compact. Applications from many other systems like Linux are easily ported to it. Limitations: designed for embedded use, not desktop. Lacks many basic desktop features for above reason. Installation requires (free) registration at comapny's website. Commercial use would require purchase of a (very expensive) license.

DR-DOS - 100% compatible MS-DOS clone. Includes many features that MS-DOS didn't support. Limitations: does not come with a graphical user interface. Only capable of single-tasking without some complex TSRs. Limited support for modern hardware.

Server


QNX - POSIX-compliant; highly secure. Many web server packages have already been ported to it. Limitations: commercial use would require purchase of a (very expensive) license.

Embedded



QNX - realtime, portable, highly reliable. Limitations: commercial use requires purchase of a (very expensive) license.


Comparison of free and open-source operating systems

Desktop / Workstation


Linux - Large selection of applications. Support for a broad range of hardware, and runs on systems both old and new. Highly reliable and secure. Growing community focusing on increasing ease of use. Limitations: Limited selection of commercial software. The large number of choices in distros and desktop environments can be daunting. Some devices do not work in Linux, simply because the vendors will not release hardware specifications.

FreeBSD - large selection of software (pretty much whatever runs on Linux). Less restrictive licensing (BSD). About 95% of hardware supported in Linux is supported by FreeBSD. Highly secure and reliable. Limitations: awkward installation of programs (except PC-BSD variant). Limited selection of commercial software. Community is highly devisive and prone to fragmentation. Some hardware devices do not work in FreeBSD due to lack of hardware documentation.

Server



Linux - reliable and secure. Very large support for commercial server software. Scales well across multiple cores and handles multi-threading well. Limitations: no support for some proprietary Microsoft extensions (like ASP).

FreeBSD - highly reliable and secure. Very large selection of commercial server software. Decent performance and hardware scaling. Limitations: no support for some proprietary Microsoft extensions. No major commercial backers.

Embedded


Linux - excellent documentation and reliability. Easily portable. Highly modular (can have unneeded components removed). Limitations: size still cannot be reduced enough for some types of devices.

eCos - designed from groun up for emdedded use. Highly portable and POSIX compliant. Limitations: ?