Code::Blocks is a free C/C++ and Fortran IDE built to meet the most demanding needs of its users. It is designed to be very extensible and fully configurable.
We provide the build of Code Blocks that includes MinGW and thus gcc (GNU Compiler Collection). Code Blocks will default to using GCC as the compiler, but other compilers are supported too.
https://www.codeblocks.org/license/
Code::Blocks is distributed under the GNU General Public License, version 3, which means it can be used freely by anyone!
The only exception is the SDK, distributed under GNU Lesser General Public License, version 3, which is allowed to be linked by closed-source plugins.