(1) See Windows XP.

(2) (EXtreme Programming) A discipline for developing software that emphasizes customer involvement and teamwork. Developed by Kent Beck, Ward Cunningham and Ron Jeffries, it is based on a formal set of rules about how one develops functionality such as defining a test before writing the code and never designing more than is needed to support the code that is written.

XP is designed to steer the project correctly rather than concentrating on meeting target dates, which are often unrealistic in this business. Some of the core practices are simple design, pair programming and delivering small releases frequently. For more information, visit www.extremeprogramming.org and www.xprogramming.com. See Scrum.

(3) (XML Protocol) XP was an earlier acronym for XML Protocol, but was superseded by XMLP due to naming conflicts with Extreme Programming and Windows XP. See XMLP.