Just a short post this one.
Somebody else may already have mentioned this, but I only just figured it out for myself – the CompilerVersion for the Delphi 2009 compiler is not what you might expect (and is not what the documentation says it is!).
Both CompilerVersion and RTLVersion have the value 20 in Delphi 2009.
In Delphi 2007 these were 18.5 and 18.0 respectively. Confusingly the documentation is correct for RTLVersion but incorrectly gives 18.0 as the value for CompilerVersion.
Is anyone else wondering what happened to 19?
Did Delphi 2008 happen after all and I just missed it?