1. UCC(Unified Code Count) is developed by the researchers at USC in C++. It is cross-platform and supports a bunch of languages. The most impressive feature to me is that it can do code complexity analysis, which is very rare for a open-source code counter.

2. CLOC(Count Lines of Code ) is written in Perl. Lightweight, easy to use.

So I would recommend every programmers to have both in their arsenal.