Richard Stallman is an American software freedom activist and programmer. He launched the GNU Project, founded the Free Software Foundation, developed the GNU Compiler Collection and GNU Emacs, and wrote the GNU General Public License.
Carl Sassenrath (born 1957 in California) is an architect of operating systems and computer languages. He brought multitasking to personal computers in 1985 with the creation of the Amiga Computer operating system kernel, and he is currently the designer of the REBOL computer language.
Rasmus Lerdorf (born 22 November is a Greenlandic-Danish programmer. He created the PHP scripting language, authoring the first two versions of the language and participated in the development of later versions
Andrew "Tridge" Tridgell (born 28 February 1967) is an Australian computer programmer. He is the author of and a contributor to the Samba file server, and co-inventor of the rsync algorithm. He has analysed complex proprietary protocols and algorithms, to allow compatible free and open source software implementations.