fork

In the open-source community, a  is what occurs when two (or more) versions
of a software package's source code are being developed in parallel which
once shared a common code base, and these multiple versions of the source
code have irreconcilable differences between them. This should not be
confused with a development branch, which may later be folded back into the
original source code base. Nor should it be confused with what happens when
a new distribution of Linux or some other distribution is created, because
that largely assembles pieces than can and will be used in other
distributions without conflict. Forking is uncommon; in fact, it is so
uncommon that individual instances loom large in hacker folklore. Notable in
this class were the Emacs/XEmacs , the GCC/EGCS  (later healed by a merger)
and the forks among the FreeBSD, NetBSD, and OpenBSD operating systems.
