Comparison of regular expression engines

This is a comparison of regular expression engines.

NOTE: An application using a library for regular expression support does not necessarily support the full set of features of the library, e.g., GNU grep uses PCRE, but supports no lookahead, though PCRE does.

• Regular expression § Implementations and running times
• Comparison of parser generators

• Regular Expression Flavor Comparison – Detailed comparison of the most popular regular expression flavors
• Regexp Syntax Summary
• Online Regular Expression Testing – with support for Java, JavaScript, .Net, PHP, Python and Ruby
• Implementing Regular Expressions – series of articles by Russ Cox, author of RE2
• Regular Expression Engines