Rex is a regular expression library which implements most of the POSIX 1003.2 specification. It is very mature and has been in heavy production use by thousands of users, on many platforms, since 2002.
ATMSP - A Tiny Mathematical Speed Parser
A Tiny Mathematical Speed Parser ATMSP is a portable C++ parser for mathematical expressions like "sin(x)+y^2" e.g. These may contain arbitrary numbers of functions, variables and constants. Major design goal was minimalistic size and maximum speed. Tiny 320 code-lines offer a parser plus bytecode-generator, 26 mathematical functions and 17 supported base-types including complex and arbitrary MPFR-multiprecision. Both parser and bytecode may run in threads. The usage of ATMSP is most simple - just include a single header in your own code and go. Reasonably experienced coders may implement other base-types like bool, SSE2, rationals or bigint's with a few changes. Have fun, Heinz van Saanen
Tools Slightly Above the Runtime
Tools Slightly Above the Runtime QueryTool for IBM i based on TSAR: http://www.ibm.com/developerworks/ibmi/library/i-extended-dynamic-sql/index.html