The original EMACS was a set of Editor MACroS for the TECO editor written in 1976 by Richard Stallman, initially together with Guy L. Steele, Jr.. Later in 1984 the GNU Emacs was released under a GNU General Public License.
X originated at MIT in 1984. The current protocol version, X11, appeared in September 1987. The X.Org Foundation now leads the X project, with the current reference implementation, X.org Server, available as free software under the MIT License and similar permissive licenses.
Most popular windowing system implementation for desktop Linux and all Unix operating systems, excluding Mac OS X
Started by Linus Torvalds, Since the initial release of its source code in 1991, it would grow from a small number of C files under a license prohibiting commercial distribution to its state in 2007 of about 290 megabytes of source under the GNU General Public License.
Many, including: Most popular kernel used by top 500 supercomputers. Most popular kernel in mobile devices sold in 2013.
The project began as a result of frustration within the 386BSD developer community with the pace and direction of the operating system's development. The four founders of the NetBSD project were Chris Demetriou, Theo de Raadt, Adam Glass and Charles Hannum.
Originally developed as the proprietary software application suite StarOffice by the German company StarDivision, the code was purchased in 1999 by Sun Microsystems. The code was made available free of charge in August 1999. On July 19, 2000, Sun Microsystems announced that it was making the source code of StarOffice available for download under both the LGPL and the Sun Industry Standards Source License (SISSL)
Descended from the Mozilla Application Suite, the project started as an experimental branch of the Mozilla Project. Originally titled Phoenix, then renamed as Firebird, the project was finally named Mozilla Firefox. The version 1.0 was released on November 9, 2004.