Numerous individuals and groups are working on free software. The scope of these systems is often broader than a commercial undertaking would consider. Here's what a quick search found:
OpenSource (tm)
"The basic idea behind open source is very simple. When programmers on the Internet can read, redistribute, and modify the source for a piece of software, it evolves. People improve it, people adapt it, people fix bugs. And this can happen at a speed that, if one is used to the slow pace of conventional software development, seems astonishing.

We in the open-source community have learned that this rapid evolutionary process produces better software than the traditional closed model, in which only a very few programmers can see source and everybody else must blindly use an opaque block of bits."

The Mozilla Organization
Netscape has opened the source code of it's browser. This means anyone can use and contribute to it. This unusual move was influenced by Eric Raymond's The Cathedral and the Bazaar paper.

GNU's Not Unix! (GNU)
"The GNU Project started in 1984 to develop a complete free Unix-like operating system. Variants of the GNU system, using Linux as the kernel, are now widely used; though often called ``Linux'', they are more accurately called GNU/Linux systems. The first test release of ``the'' GNU system, using the GNU Hurd as the kernel, was made in August 1996."

Note that GNU was initially a reaction to the closed source code of the AT&T UNIX days. With the advent of open source code for Berkeley UNIX such as FreeBSD, that need is diminished. Perhaps the greatest constibutions of GNU are the widely popular and platform-ported free GCC and G++ C and C++ compilers and development tools, the GNU Emacs editor/environment, and the distributively-open Copyleft distribution paradigm and accompanying free software philosophy.

the Free Software Foundation
The Free Software Foundation funds Richard Stallman's GNU project. This site includes useful links and documents about developing and distributing free software, including the Copyleft open distribution paradigm.

Gnome -- GNU Network Object Model Environment
"The GNOME project intends to build a complete, user-friendly desktop based entirely on free software." GNOME is part of the GNU project and OpenSource (tm) movement.

KDE -- the K desktop environment
"KDE is a powerful graphical desktop environment for Unix workstations. It combines ease of use, contemporary functionality and outstanding graphical design with the technological superiority of the Unix operating system."

the Hungry programmers
Building a free SQL server, Java VM & tools, web browser, windowing system, etc.
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