A new C/C++ IDE (development environment) was recently made available for download, by the folks at JetBrains, who have developed some impressive commercial coding tools. It's called
CLION.
It's cross-platform, running on windows, mac, and linux -- but note that this means it will run on these platforms, NOT that you can use it on one platform to target another.
It's also a commercial tool as far as I can tell -- which is currently available for free early (beta) testing -- someone let me know if this turns out to be wrong.
Looks interesting -- one appealing aspect is that it seems to use a relatively-standard build/project system (cmake), and uses the standard gcc compiler, making it more compatible with standard c++ coding.
See also: Qt, Dev-C++ (free and open source), Codeblocks (free and open source), Visual Studio, C++ Builder.
http://www.jetbrains.com/clion/