DEELX regular expression

DEELX is a Perl-compatible regular expression engine in the C environment. is a research and development project conducted by RegExLab.
Basic Features:
Supports Perl-compatible regular expression syntax.
Supports common matching modes such as IGNORECASE, SINGLELINE, MULTILINE.
It has strong compatibility and can be compiled in most C environments such as vc6, vc7, vc8, gcc, Turbo C, etc.
Supports multiple advanced features such as named grouping, conditional expressions, recursive expressions, etc. (New features in version 1.2)

Compared with GRETA and boost, DEELX is unique:

Completely written using template libraries, supporting char, wchar_t, int, etc. and other base type versions.
All codes are located in one header file (.h), which is simpler and more convenient to use than any other engine.
Supports right-to-left matching mode, searching for matches from the end of the text forward.
This prevents infinite loops caused by zero-length submatches looping infinitely. (New features in version 1.2)

DEELX shortcomings:

DEELX is a completely free lab product.
In order to make up for the shortcomings of laboratory products, this site has simultaneously launched a debugging tool that is fully compatible with this engine: Match Tracer.