This C compiler is compiled at the same time the C compiler compiles your program. In other words, it compiles C at compiler compile time, where with other C compilers the program's compile time is the compiler's run time.

Hope this helps.

No, the C compiler executable compiles your program at run time, i.e. when the compiler is running. This C compiler compiles your program while the compiler is being compiled (well, you never end up with a compiler executable, just your compiled program).

This is a C compiler implemented in C++ template metaprogramming. (Well, technically constexprs, but similar)