I haven't done a lot of programming in languages other than BASIC, so I will need to learn at least some C and Pascal along the way.
One of the reasons I chose ACK is that it is designed to be expandable. You can add new targets and/or new programming languages. The existing BASIC included with ACK is very minimal though.
FreePascal is designed to be a cross-compiler, but only for various Pascal languages. There is a
Decimal BASIC to FreePascal converter though, which could be useful, as Decimal BASIC is based on ANSI Full BASIC as IS-BASIC was.