An operating system based on the best Windows NT design principles
ReactOS is an open source effort to develop a quality operating system that is compatible with applications and drivers written for the Microsoft Windows NT family of operating systems (NT4, 2000, XP, 2003).
Perix is a 16/32 protected mode kernel, bootable and capable of running without an operating system. It is written in Turbo Pascal 7.0 for DOS, Delphi 7.0, Pascal Pro, Virtual Pascal v2.1, TASM and JWASM. Turbo pascal version can be used as kernel on its own, or as a second stage loader to external programs. I would like to announce, that the first attempt to put the Delphi 64bit to work was successful. As soon as possible I will place at the disposal a very small 64bit kernel version.
Sinhala Desktop is a Sinhala Version of Windows Shell Replacement. This project contains all the major Windows System components with Sinhala User Interface. (Sinhala is a national language of Sri Lanka.) Developed Using Delphi 6 and C++Builder 6.
FreeOS/1 is a Free, Open Source, FreeDOS based Free and Open Source Alternative OS, with open source Microsoft Windows compatibility using HXDOSExtender KernelEx,and ReactOS source code. FreeOS/1 will include new technologies and will be easy to use
A techonogically advanced engine using C++ and ASM as languages.
A techonogically advanced engine using C++ and ASM as languages, with improved performance and a almost virtually infinite triangle count support, even on slower and older machines. It haves a full shader system, physics system (DOE Based), 100% physically correct lightning and colour grading, and supports various popular formats in 3D modelling and gaming scene. It was previously under a heavy eula policy, but now is under GPL because of internal problems.
The Danber project aims to create an operating system where both Windows and Linux programs can be run: it is a Windows NT based kernel, but with UNIX user mode compatibility. Support for both PE and ELF executable formats.
FreeMiNT is a free alternative OS kernel for Atari systems & clones
FreeMiNT provides the basis of a free TOS compatible replacement OS that can multitask. Used together with the free system components fVDI (device drivers), XaAES (graphical user interface widgets), and TeraDesk (desktop manager), it provides a modern user interface.
The Isis OS Project Is a Controlled Project to Develop An Advanced Modern Operating System!
Perix is a free public domain MS-DOS compatible operating system written in Turbo Pascal and Assembly. Multi tasking, parallel data transfer and extended memory support. All parts of system are distributed under terms of the GNU license.