Aaron used Delphi. Don't ask me how I remember after something like a year and a half or two years, when he made a comment about it to the SE4 ideas list when there was a small arguement about the difficulty of certain features, mainly people who thought they knew how to program (I admit I was among them at the time
).
I'm fairly sure SE1 was done in VB, an earlier Version if I remember, like 2 or 3. SE2 was VB 4 or 5 (I think
), SE3 used Delphi, SEIV used Delphi.
Oh, and just so everyone knows, VB is evil.