PERL5 Regular Expression Description
- Detailed description written by Tom Christiansen in response to a question posted to comp.lang.perl.misc.
- http://people.bath.ac.uk/ccsnad/perl/everything_to_know/regexps.html

perl.perl6.language.regex
- Archive of discussion relating to regular expressions in Perl 6.
- http://www.nntp.perl.org/group/perl.perl6.language.regex/

Regular Expressions
- A description of the patterns used in Perl for pattern matching.
- http://www.cs.cmu.edu/People/rgs/pl-regex.html

Perldoc.com - perlretut
- A tutorial for regular expressions in Perl.
- http://perldoc.perl.org/perlretut.html

Perldoc.com - perlre
- Describes the syntax of regular expressions in Perl.
- http://perldoc.perl.org/perlre.html

Perl FAQ : Regular Expressions
- Pattern matching and regular expressions.
- http://perldoc.perl.org/perlfaq6.html

Perl Regex
- An introduction covering basic concepts.
- http://www.anaesthetist.com/mnm/perl/regex.htm

perlretut
- Basic tutorial, distributed as part of the core documentation.
- http://www.cs.rit.edu/~afb/20013/plc/perl5/doc/perlretut.html

Perl Regular Expression Tutorial
- A tutorial that shows how to use Regular Expressions in Perl.
- http://virtual.park.uga.edu/humcomp/perl/regex2a.html

MakeRegex
- The Perl-module by Hakan Kjellerstrand composes a regex-expression from a list of words.
- http://www.hakank.org/makeregex/

Perl Regular Expression Matching is NP-Complete
- A discussion of the complexity of regular expression matching algorithms in Perl.
- http://perl.plover.com/NPC/

Dirty Secrets of the Perl Regex Engine
- Slides from a talk the author presented at TPC and YAPC. Covers the /o flag and re 'eval'.
- http://perl.plover.com/yak/dirty/

How Regexes Work
- An article about how to use regular expressions in Perl by M-J Dominus.
- http://perl.plover.com/Regex/

Perl Regular Expression Quick Reference
- One-page document containing tabulated summaries of common codes, modifiers, and special characters. [PDF]
- http://www.erudil.com/preqr.pdf