While [The Simple Library]'s SimpleTest
[http://simpledevlib.sourceforge.net/packages/SimpleTest.txt]
largely duplicates [tcltest]'s functionality, it does so "in the form
of a [package] with its own [API].  The simpletest application
[http://simpledevlib.sourceforge.net/utilities/simpletest.html]
is no more than a frontend to the SimpleTest package, and it
is pretty easy to write any other frontend suited to
particular needs."