C unit testing
The approach to unit testing frameworks used for Check originated with Smalltalk, which is a late binding object-oriented language supporting reflection. Writing a framework for C requires solving some special problems that frameworks for Smalltalk, Java or Python don't have to face. In all of those language, the worst that a unit test can do is fail miserably, throwing an exception of some sort. In C, a unit test is just as likely to trash its address space as it is to fail to meet its test requirements, and if the test framework sits in the same address space, goodbye test framework.
To solve this problem, Check uses the fork() system call to
create a new address space in which to run each unit test, and then
uses message queues to send information on the testing process back to
the test framework. That way, your unit test can do all sorts of
nasty things with pointers, and throw a segmentation fault, and the
test framework will happily note a unit test error, and chug along.
The Check framework is also designed to play happily with common development environments for C programming. The author designed Check around Autoconf/Automake (thus the name Check: make check is the idiom used for testing with Autoconf/Automake), and the test failure messages thrown up by Check use the common idiom of filename:linenumber:message used by gcc and family to report problems in source code. With (X)Emacs, the output of Check allows one to quickly navigate to the location of the unit test that failed; presumably that also works in VI and IDEs.