PCRE is a widely used Unicode-compatible regular expression engine. It implements Perl5 regex syntax and semantics, some Python, .NET and Onigurama extensions. It uses just-in-time compilation, has consistent escaping rules, and allows for recursion, assertions and conditional patterns or complex subroutines and callouts, thus goes far beyond classic regular expressions.
minor bugfix: A few more and tidies. The only change of real note is the removal of The actual POSIX names regcomp etc. from the POSIX wrapper library because These have caused for some applications (see 10.33 #2 below).