Code::Blocks is an open source, cross-platform and free C/C++ IDE.
It is build using the wxWidgets GUI library.

The WEB site states:
 "Code::Blocks is a free C++ IDE built specifically to meet
 the most demanding needs of its users. It was designed, right
 from the start, to be extensible and configurable."

LICENSE: GPL3 or later (IDE)
LICENSE: LGPL3 or later (SDK)

WWW: http://www.codeblocks.org/