Bloodshed's Dev-C++ is a fully featured IDE for the C/C++ programming language. It uses MinGW port of GCC (GNU Compiler Collection) as it's compiler. Dev-C++ can also be used in combination with Cygwin or any other GCC based compiler.

wxDev-Cpp is an extended version with an included wxWidgets formdesigner.

For a nice IDE under Linux have a look at Anjuta.