C++ Compiler for Windows without IDE? [closed]
MinGW. It's GCC/G++ for Windows. It's much lighter than Cygwin. The main difference from Cygwin GCC is that it doesn't try to emulate UNIX APIs, you have to use the Windows APIs (and of course the standard C/C++ libraries). It also doesn't provide a shell and utilities like Cygwin, just the compiler.
There is also a related system called MSYS, which provides a shell, etc. like Cygwin, but this is not required. MinGW itself will run in CMD (but I highly suggest using something better like Bash, for your own sanity).
Visual C++ has a command line compiler, cl:
If you don't have Visual Studio, you can download the Windows SDK (newer version) or the Windows Driver Kit for free, and then use the CL.EXE command-line compiler as suggested by @Greg Hewgill.