More than 20 years ago, I used a C interpreter called EiC.

Hmm, someone tried to resurrect it on SourceForge a couple of years ago, it seems, but it's dead again.

http://sourceforge.net/projects/eic/

Someone threw it on GitHub:

https://github.com/kungfooman/EiC-C-Interpreter

PDF of doc [2009]:

http://www.mirrorservice.org/sites/downloads.sourceforge.net...