The first programming language I used professionally was Perl. It was the popular and versatile scripting language of its time (late '90s). I used Perl in UNIX environment. In Windows environment, I used Visual Basic (VB6) and Classic ASP (which was just “ASP” at the time ).
Then .NET Framework came out, and Windows-based servers became more stable and common. (That’s when we started distinguishing “Classic” ASP from ASP.NET). I’ve been doing .NET development ever since.