Many moons ago, I wrote about a few opensource IDE's I've encountered for building C++ code. I just wanted to update the record to say that I have now been using NetBeans as my preferred IDE for C++ development.
The interface is multi-window, has good compile time error messages, has some built-in performance monitoring indicators, does debug single-stepping easily, and overall handles itself quite well for modularizing and maintaining code. The make system is also easier to work with.