Originally coded in BASIC V2, this is a so called "micro compiler" for the Commodore 64.
It compiles a sub-set of BASIC V2 into quite fast machine code. You can find more details
in the (german) description from back in the days.
This version has been compiled from BASIC V2 into Javascript using MOSpeed.
So it runs and compiles natively in your browser.
Error handling of this version is quite limited. It will detect and report errors,
but it won't display exactly where they were.
The compiler takes PRG files only. Here are three examples written in BASIC V2 that you can use for testing:
Enough talking, let's compile some things...