Seeing With C - Technical article about regular expressions. Discusses types of automata, searching, parsing, validating. GNU Emacs - Documentation for regex in Emacs Lisp. Describes the functions. Digital Amit - Introduction to regex. Presents syntax and examples. GNU Awk User's Guide - Regex manual pages for Awk. Discusses syntax, dynamic regexps. So What's a Regular Expression Anyway - Introduction to regex. Presents syntax, code samples. PCRE Wrapper for Delphi 7 - Wrapper classes to support PCRE in Delphi. Includes download links. Regular Expressions - Notes from computer science class about TCL. Presents the Chomsky hierarchy, finite automata and regular expressions. Unicode Regular Expressions - Unicode Technical Standard document. Describes guidelines for extending regex engines to use Unicode. C# Regular Expressions - Article by O'Reilly author. Presents classes, engine details and sample expressions. Flagrant Badassery - Blog of Steven Levithan. Discusses the Regex Cookbook by Levithan and Jan Goyvaerts, regex APIs and regex recipes. Regular Expressions Cheat Sheet - One-page reference. Presents major points of regex syntax. Four Guys from Rolla - Articles about regular expressions. Includes articles about parsing, validating and replacing. Finite Automata and Regular Expressions - Notes from computer science class. Compares regular expressions to finite automata. .NET Framework Regular Expressions - MSDN documentation. Features detailed examples, list of references. The Code Project - Collection of articles. Features tools, general techniques and regex implementation in various languages. Zvon.org - Regex resources. Features tutorial, reference and glossary. Advanced Regular Expression Tips and Techniques - Blog post. Discusses techniques such as commenting, callbacks, lookarounds, conditionals and named patterns. MySQL Regular Expressions - Manual page for MySQL regex. Features operators and character classes, includes user comments. StackOverflow Tagged Questions FAQ - Collection of questions and user-submitted answers. Features ratings for each answer and comment. Regular Expressions in Grep Command - Series of two articles about regex in the Unix Grep command. Features examples of text searches. Regular Expressions in Grep - Tutorial on nixCraft blog. Features syntax, tricks, comments. PHP Manual - Regex section of the PHP manual. Covers PCRE engine, pattern syntax, PHP functions, and includes user comments. PHPFreaks - Regex board on PHP forum. Features user-contributed questions and answers. Regular Expression HowTo - Python regex tutorial. Focuses on the re module. Haskell - Review of regex libraries in the Haskell programming language. Includes feature matrix and benchmark.