CUnit
 
Lightweight system for writing, administering, and running unit tests in C.

Website: http://cunit.sourceforge.net/
Platforms supported: Win32, Linux, FreeBSD, Haiku
Headers to include: CUnit/CUnit.bi
Header version: 2.1-3
Examples: in examples/misc/CUnit/

Haiku R1 beta 6 amd64: `examples/misc/CUnit/simple.bas` compiled and ran
with FreeBASIC 1.20.4-3 against HaikuPorts BCUnit 3.0.2 (`libbcunit`). Both
tests passed with five assertions.