What is it all about?
The Perl Compatible Regular Expressions (PCRE) library is a set of functions that implement regular expression pattern matching using the same syntax and semantics as Perl 5. PCRE has its own native API, in addition to a set of POSIX compatible wrapper functions.
* The PCRE library is free, even for building proprietary software. * PCRE including Apache, PHP, KDE, Postfix, Analog, and Nmap. * Open Source & Easy to use.