In the past I worked a lot with Visual Basic (6.0), as it was just about the only programming language I knew (except Qbasic, which is the first language I learned). I used that language nearly to it's limits.
Most programs are not completely finished, so the programs may have non obvious behavior (some programs don't even have an exit function as I often used [ctrl] + [break] instead), none of them is documented and they have hardly been tested.