I've worked in environments where classic ASP, .NET 1.0, .NET 3.5 and 4.0 are all in production, some on the same server. I imagine there are similar tales rega

I've worked in environments where classic ASP, .NET 1.0, .NET 3.5 and 4.0 are all in production, some on the same server. I imagine there are similar tales regarding production environments for Java and Ruby etc. If you cannot run different versions simultaneously you have a problem. Thankfully you can.