autoconf in Cygwin

Cygwin installer allows you to select latest or stable version of autoconf.

Autoconf uses M4 macros (thanks Kernighan and Ritchie) to produce shell scripts which in turn automatically configure source code packages. M4 converts input to output expanding macros as it goes (here's how). If there are no macros, well, the input is the output.

M4 needs to be installed before autoconf. Perl is also a prerequisite.

gperf in Cygwin

GNU gperf is a perfect hash function generator.

It was written by computer scientist Douglas Schmidt. The code is available under a copyleft license and is not allowed to be used within proprietary software.

Sidebar - what is a perfect hash function?

A perfect hash function has both a computer science meaning and a mathematical meaning, both of which are equivalent. It maps distinct elements in a set S to a set of integers with no collisions (mathematically; an injective function; or one-to-one function).

Sidebar - what is a perfect hash function generator?

A perfect hash function generator takes source data (list of keywords, let's say size N) and creates a (perfect) hash function.