What are regular expressions? Will they use features such as lookaheads, lookbehinds, backreferences, reluctant quantifiers, atomic groups, custom quantifiers, etc. Etc.?
Other respondents are associated with the regex-dna regular expression , but it uses only the most basic functions common to all regular expression flavors, such as Kleene star ( * ) and alternating ( | ). Thus, while the GNU C / C ++ implementations seem like clear winners, they won’t be useful if you need any of the features listed above.
Another consideration is Unicode support. If you are dealing with actual text (and not data presented as text, as in the regex-dna test), you should use a regular expression flavor with good Unicode support.
I suggest you take a look at C #. Emulating .NET regular expressions does not have a reputation for being slow (which is the only reasonable thing to say about IMO regular expression speeds), and for mission-critical applications, it provides the ability to directly compile byte code to significantly improve performance.