I’ve started a new Twitter account @PerlRegex for Perl regular expressions. My original account, @RegexTip, is for regular expressions in general and doesn’t go into much detail regarding any particular implementation. @PerlRegex goes into the specifics of regular expressions in Perl.
Why specifically Perl regular expressions? Because Perl has the most powerful support for regular expressions (strictly speaking, “pattern matching.”) Other languages offer “Perl compatible” regular expressions, though the degree of compatibility varies and is always less than complete.
I imagine more people have ruled England than have mastered the whole of the Perl language. But it’s possible to use Perl for regular expression processing without learning too much of the wider language.