Manhattan Virtual Classroom
The Manhattan Virtual Classroom is a fast, stable and effective course management system that runs on Linux and other Unix-like systems. It's written entirely in the C programming language (fast! - light hardware requirements) and is 100% database-free (no MySQL administration, no tuning issues- simple!) Manhattan supports thousands of users at its Western New England College home, and at other colleges and schools around the world.
(source: official website)
English as Second Language journal article: http://www.tesl-ej.org/wordpress/issues/volume7/ej26/ej26m2/