Fork (software development)

A spin-off (even Fork, English fork = fork, commonly used in the masculine ) is in software development is a development branch after the split a project into two or more follow-up projects; the source code, or portions thereof are hereby further developed independently of the original parent project. With respect to copyright is also from a derivative ( derivatively, Latin: derivare derived ) spoken.


Spin-offs are mainly held in free software projects, since in these the rights to develop and change is the license itself usually possible. In closed-source projects can occur splits when several companies work together and the - possibly new - share rights to the product.

Examples of projects

( Examples of projects that have emerged from splitting )

  • The NTFS file system is based on HPFS, the file system of OS / 2
  • The free (now known as Apache OpenOffice ) seceded from StarOffice, which was further developed commercially until 2010.
  • LibreOffice split from, after Sun Microsystems ( the original developer ) was acquired by Oracle.
  • The web content management system Joomla originated from Mambo.
  • The editor XEmacs, emerged from Emacs.
  • The compiler EGCS originated from GCC.
  • The Internet browser Mozilla has many subsidiary projects, some of which are Mozilla Firefox and Galeon, which in turn was divided: Epiphany.
  • The Multimedia Player MPlayerXP emerged from MPlayer.
  • VNC was from 2002 with version 3.3. chargeable. As a result, more implementations developed under the GPL, using the same protocol.
  • The file sharing software aMule ( eDonkey network ) emerged from xMule.
  • The peer-to -peer software FrostWire emerged from LimeWire.
  • The BSD derivative OpenBSD emerged from NetBSD and places higher value on security than the parent project. Likewise, DragonFly BSD emerged from FreeBSD.
  • X.Org emerged from XFree86, introduced with version 4.4 a different license its developers.
  • The composite window manager Beryl has arisen following a disagreement within the ranks of Compiz. Both projects are now united under the name Compiz Fusion again
  • Libav emerged due to infighting among the developers of the project FFmpeg and replaced this in Debian and Ubuntu.

Version control systems

In version control systems, a spin-off is generally not the result of dispute among developers or inactivity of a project, but in the context of branches ( branches ) regularly work means to contribute innovations for a project. With distributed version control systems, the possibility is added to be able to create branches without write access to the original version management system. There to Linus Torvalds ' kernel Linux solely on the software developer platform GitHub more than 350 spin-offs which are for the most part not designed to be developed independently but that their individual innovations back into the original project - or more accurately in the original sources (or repositories ) are introduced. Such branches are correspondingly more internal Forks.


In copyright law, which also applies to software, the term derivative has exactly the same meaning as in all other areas. This means for example that a derivative of a software as long as no authorization is given by the rights owner of the software, only under certain conditions created (eg error correction ) ( depending on country, eg by EU directives regulated) and in particular, may not be distributed. That is, as long as the license of software not explicitly allowed that derivatives may be produced or distributed where prohibited. This also plays in the case of SCO against Linux an important role, because SCO has declared AIX as well as the Linux kernel with system software to unauthorized Unix derivatives. Although it is indeed debatable whether SCO these rights has ever, SCO, as long as there is no copyrighted code in the GNU / Linux system, no condemnation, for example for a Linux distributor, obtain on the basis of copyright.