GNU's free version of the scanner generator Lex
AT&T Lex is the classical scanner generator that comes with Unix. This is an official man page.
re2c is a tool for generating C-based recognizers from regular expressions. The generated code is not tied to any particular input model.
Lex-compatible scanner generator that supports the generation of scanners which process 16-bit character input.
by John David Stone
Resources on the Web
by Etienne Bernard
Gobo Eiffel Lex is a tool for generating Eiffel programs that perform pattern-matching on text. Gelex reads a given input file for the description of the scanner to be generated. The description is in the form of pairs of regular expressions and Eiffel code, called rules. Gelex generates as output an Eiffel class equipped with routines to analyze input text for occurrences of the regular expressions. Whenever one is found, the corresponding Eiffel code is executed.
YooLex is a Lex tool that generates C++ STL compatible codes. The purpose of this program is to provide a good way of creating scanner classes that is capable of running multiple instances concurrently. Currently YooLex is at the alpha stage, so your advices and supports are very well come. The software is free.