An online tool to test regular expressions. It allows a user to input a regular expression along with some text and displays the parts of the text that match the regular expression.

A tutorial for regular expressions in Perl.

Perl regular expressions quick start; Covers the very basics of understanding, creating and using regular expressions

Describes the syntax of regular expressions in Perl.

Archive of discussion relating to regular expressions in Perl 6.

An useful ready reference - with informative tips - for those who use Perl regular expressions regularly.

A quick introduction to Perl regular expressions for those who have some programming experience.

One-page document containing tabulated summaries of common codes, modifiers, and special characters.

A discussion of the complexity of regular expression matching algorithms in Perl.

Notes and slides from a two part talk that, in its first part, details the algorithm that perl uses internally to do regex matching and, in its second part, discusses practical parsing applications and RegEx optimization