It is free software under GNU GPL license. This application is available under GNU GPL license. It used the FreeBSD kernel and GNU userland. It is released under the GNU GPL. GCC is licensed under version 3 of the GNU General Public License. XEmacs is a variant that branched from GNU Emacs in 1991. The system is also capable of running GNU/Linux operating systems. The name GNU is a recursive acronym for "GNU's Not Unix". The version of codice 1 bundled in GNU coreutils was written by David MacKenzie. The version of codice 1 bundled in GNU coreutils was written by Jim Meyering. GNU linker is free software, distributed under the terms of the GNU General Public License. Line editing and history support based on GNU Readline is optional. It was created by GNU Project founder Richard Stallman. The above directives are available in compilers from Microsoft, Borland, GNU, and many others. It also added support for GNU Assembler syntax.