The GNU Compiler Collection (GCC) is a compiler system produced by the GNU Project supporting a wide variety of programming languages and architectures. GCC’s external interface follows Unix conventions. Each of the language compilers is a separate program that reads source code and outputs machine code. All have a common internal structure. A per-language front end parses the source code in that language and produces an abstract syntax tree (“tree” for short).
For a full list of supported languages and architectures go to GCC’s WIkipedia page.