CMDebug is a 32-bit or 64-bit GUI application.
TCC-RT is a 32-bit or 64-bit console (character-mode) application.
Both are designed to run under Windows 7, 2008R2, 8, 2012, and 10.
The 32-bit and 64-bit versions of CMDebug are identical in features. The CMDebug installer will automatically choose the appropriate version for your version of Windows.