reactos is a free, opensource reimplementation of windows

since 1983, developing the free unix style operating system gnu, so that computer users can have the freedom to share and improve the software they use.

debian is an operating system and a distribution of free software. it is maintained and updated through the work of many users who volunteer their time and effort.

FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms.

The official home of the Python Programming Language

GIMP - The GNU Image Manipulation Program: The Free and Open Source Image Editor

the official home page of the apache openoffice open source project, home of openoffice writer, calc, impress, draw and base.

pcjs offers a variety of online machine emulators written in javascript. run dos, windows, os/2 and other vintage pc applications in a web browser on your desktop computer, iphone, or ipad. an assortment of microcomputers, minicomputers, terminals, programmable calculators, and arcade machines are also available, along with an archive of historical software and documentation.