(computing) Initialism of Dell XPS (a line of gaming and performance computers manufactured by Dell) / (computing) Initialism of XML Paper Specification.

(chemistry) Initialism of extruded polystyrene foam. / (communication, computing) Initialism of transmit packet steering (a scaling technique for network traffic processing)

(software engineering) Initialism of Extreme Programming. / (medicine) Initialism of Xeroderma Pigmentosum.

(role-playing games) Initialism of Experience Point.

(motor racing) Abbreviation of extreme prix; xPrix.; from being an extreme grand prix.

(computing) Ellipsis of Windows XP.

(aviation, military, obsolete, US) eXperimental, Pursuit, fighter (prefix)

(grammar, X-bar theory) Initialism of X Phrase. (a phrase which consists of either: (1) an optional specifier and an X-bar phrase, or (2) a conjunction sandwiched between two other XPs. The X is a "pro-letter" which can be substituted by letters such as N for noun, V for verb, P for preposition, I for inflectional, etc.)

plural of XP ('X Phrase')

(aviation, military, US, historical) The original designation of the Lockheed XF-90, redesignated in 1948.