XSB has an efficient interface to POSIX pattern regular expression and wildcard matching functions. To take advantage of these features, you must build XSB using a C compiler that supports POSIX 1.0 (for regular expression matching) and the forthcoming POSIX 2.0 (for wildcard matching). The recent versions of GCC and SunPro compiler will do, as probably will many other compilers. This also works under Windows, provided you install Cygnus' CygWin and use GCC to compile.