I second the emotion on Python. I don't understand why there is not a central repository of open source code to create idf files. I have code just sitting around, I am sure you do too, or are thinking about it. Why not share it on sourceforge? Just curious why all the idf making only happens at the labs and at DesignBuilder, etc? More of a general thought that has no answer, but would be interested to hear people's opinions.
I also like python because you can tie it to C# via IronPython. Gives a lot of leverage for me personally to be able to use an easy to use language like python and also have access to all of Microsoft's frameworks. I don't know if Perl has something like that.