Source : WordNet®

XC
     n : the cardinal number that is the product of ten and nine
         [syn: {ninety}, {90}]

Source : Free On-Line Dictionary of Computing

XC
     
        A {declarative} extension of {C++}.
     
        ["XC - A Language for Embedded Rule Based Systems", E. Nuutila
        et al, SIGPLAN Notices 22(9):23-32 (Sep 1987)].