CWEB
CWEB is a computer programming system created by Donald Knuth and Silvio Levy as a followup to Knuth's WEB literate programming system, using the C programming language (and to a lesser extent the C++ programming language) instead of Pascal.
Like WEB, it consists of two primary programs: ctangle, which produces compilable C code from the source texts, and cweave, which produces nicely-formatted printable documentation using TeX.