XPXP may stand for:
- Extreme Programming.
- Experience points in a role-playing game or in Everything2
- AMD Athlon XP CPU
- as the Chi Rho, the symbol that the emperor Constantine I saw in the sky before the Battle of the Milvian Bridge in 312. First two letters in Christ in Greek, therefore symbolic of Christianity. See Labarum.
- Windows XP operating system. The official Microsoft explanation for this name is a derivation from "experience"; another notes that "Cairo" was Microsoft's codename for an object-oriented operating system that would eliminate completely MS-DOS code from Microsoft Windows; Windows XP (chi-rho) completes the process.