| OS | License | Platform | Developement Status |
| AdaOS | GPL/LGPL/GFDL | i386 | Early stages |
| AROS | AROS PUBLIC LICENSE | x86, Amiga, m68 | Slow but Active. |
| AtheOS | GPL | x86 | This OS is being actively developed. Support Intel, AMD and other compatible processors. |
| BSD | BSD | - | See OpenBSD/FreeBSD/NetBSD for development status. |
| Cefarix | GPL | i386 | The Project is inactive |
| Chaos | BSD | x86 | Since chaos is fairly new, the hardware support is rather limited.Not much documentation. |
| CP/M | Freeware | 68000, 8086 | No development seems to be happening here. Caldera currently holds the rights to this OS. They have released the original source code but not under the GPL. Source code is available for CP/M 2 and 3 for the PCW16. |
| Darwin | Apple Public Source | PowerPC | Quite active. Apple is working hard here and is also giving back a lot of
code to the open source community. Support for the Intel platform is also
planned. |
| DCP | Unknown | x86 | Development was discontinued in the early 90s. |
| Debian GNU/Hurd | GNU GPL | x86 | Actively developed. Debian GNU/Hurd is not officially released yet, and won't be for some time. |
| E.R.I.K.A | GPL | x86 | Not very active. |
| eCos | GNU GPL | ARM, Hitachi H8300, Intel x86, MIPS, Matsushita AM3x, Motorola 68k, PowerPC, SuperH, SPARC and NEC V8xx | Very active. |
| ELKS | GNU GPL | 8086, 80286 | Not very active. |
| ERaMS | GPL | x86 | Not very active |
| EROS | GNU GPL | Intel 486 and higher | Code is complete, not very active. |
| Fiasco | GPL | x86 | Quite an active development project. |
| Free-VMS | GNU GPL | x86 | Development is slow. |
| FreeBSD | BSD | x86, DEC Alpha, IA-64, PC-98 and UltraSPARC | It works on a wide platform and it is under active development and support. |
| FreeBSD | BSD | x86, DEC Alpha, IA-64, PC-98 and UltraSPARC | It works on a wide platform and it is under active development and support. |
| FreeDOS | GNU GPL | Intel | Very active. The site is up to date. Not as bad as most of the other free operating systems that seem to have sunk into oblivion. Still does not
have multitasking, protected mode. Works under DosEmu. |
| Freedows | GNU GPL | Intel | The project is almost dead. No development has happened recently. |
| Linux | GPL | Intel, Alpha, SPARC, PowerPC | Very active. Some big names are behind it so expect a lot from this OS. |
| Menuet | GPL | x86 | Not very Active |
| Minix | BSD | Intel | Minix is upto V2.0 but the page was last updated in 1996. |
| MorphOS | Open Source | Amiga | The first release has been sent to some selected developers for evaluation
on their hardware. There is a lot of expectation from this OS. |
| NetBSD | BSD | alpha, amiga, arc, arm26, arm32, atari, bebox, cobalt, hp300, hpcmips, i386, luna68k, mac68k, macppc, mipsco, mvme68k, news68k, newsmips, next68k, ofppc, pc532, pmax, prep, sgimips, sh3, sparc, sparc64, sun3, vax, x68k | This is definitely an active project. New work is being done all the time
and all documentation and FAQs are current. Release schedules are quite
slow though. |
| NetBSD | BSD | alpha, amiga, arc, arm26, arm32, atari, bebox, cobalt, hp300, hpcmips, i386, luna68k, mac68k, macppc, mipsco, mvme68k, news68k, newsmips, next68k, ofppc, pc532, pmax, prep, sgimips, sh3, sparc, sparc64, sun3, vax, x68k | This is definitely an active project. New work is being done all the time
and all documentation and FAQs are current. Release schedules are quite
slow though. |
| Oberon | General ETH Oberon S | x86, Alpha | The project is very active. |
| OpenBEOS | aq.php?list=all&prog | x86 | This is the unofficial release ofter the original BEOS company got acquired. This is actively developed by fan followers. |
| OpenBSD | BSD | Alpha, Amiga, HP300, i386, mac68k, mvme68k, pmax, powerpc,SPARC, sun3,vax | Active development with developers all round the world. The project is
always on the lookout for more resources and help so see if you can get in
and help them out. |
| OpenBSD | BSD | Alpha, Amiga, HP300, i386, mac68k, mvme68k, pmax, powerpc,SPARC, sun3,vax | Active development with developers all round the world. The project is
always on the lookout for more resources and help so see if you can get in
and help them out. |
| Plan 9 | Plan 9 | Intel, Mips, DEC Alpha, and Power PC | This OS was recently released to the open source community but it seems to
have been a bit too late. There has not been much interest in this
promising OS. |
| PowerOS | Open Source | PowerPC | PowerOS is currently under development. Not very active |
| QNX | QNX Open Community | x86 | This was originally a commercial project. Definitely very well supported
and very actively developed. |
| ReactOS | GNU Copyleft | Intel | Actively developed. |
| RTEMS | Open Source | Motorola PowerPC, M683x0, M680x0, Coldfire; Intel ix86, i960; MIPS R46x SPARC; Hitachi SH; AMD 29K; HP PA-RISC | Very active. Beta 4.5.0 was released on 23 May 2000. There is also a
active development community behind this. |
| S.Ha.R.K | GPL | x86 | This project is very active. |
| SkyOS | freeware | | Version 5.0 is now available for distribution to beta testers. Users may download previous versions for free. |
| Solaris 8 | Solaris 8 BCL | Intel, Sparc | This is a very mature project. Actively developed and supported. |
| Unununium | BSD | i386 | This is being actively developed. |
| V2_OS | GNU GPL | Intel i386 | Quite an active project and some good code has come out of it too. |
| VSTa | Copylefted | i386, Amiga 68030 | Not very actively developed. |
| Winmac | GPL | Intel | No files have been released as yet. |
| xMach | LGPL | x86 | There is a small developer team here and they're actively looking for more
coders. |
| xMach | LGPL | x86 | There is a small developer team here and they're actively looking for more
coders. |
| Yamit | BSD | | Early releases of the microkernel are available for download. |
| ZotOS | | x86 | Not very active |