Coliru, online C++ compiler
Coliru does not only provide a web app where you can paste your code and test it with GCC or Clang. They also offer their API so you can request compilation from your own scripts (although it only handle one request at the time and it takes between 5 - 10 seconds to complete the request)
It also supports the latest features of the language that come with the C++17 revision, so it's a great place to test all these new things in a secure, isolated environment.
And it does not stop at that. Their website is also a door to a limited Linux sandbox where you can actually run some commands like
ls. This is helpful if you want to compile multiple .cpp files.
A set of key shortcuts can be used to trigger basic commands
A web browser (preferably desktop)
- GCC and Clang support
- Multiple files can be compiled
- Key shortcuts to start compiler
- Compile with Curl or AJAX through their API