The Turbo Pascal IDE. At first I thought it was stupid to have to compile a program instead of just writing it in BASIC, which was what I was used to. Then I le

The Turbo Pascal IDE. At first I thought it was stupid to have to compile a program instead of just writing it in BASIC, which was what I was used to. Then I learned to love that almost instant compile and insane speed compared to BASIC. When I was forced to move to Windows, Delphi was there to make it damned easy to build GUI apps, which was about a similar step in productivity as Turbo Pascal. They used the perfect amount of OOP to get the job done, but not bury you in abstraction.