The Python Language
Even though I am a fan of writing my scripts in Perl (for sys admin tasks etc), I believe I will have to bow and admit that Python is an excellent object-oriented and interactive programming language. The power of the Python language, I believe ( Created and authored by the brilliant mind Guido Van Rossum) is its simplicity and clear syntax. As I am far from a hard core Python coder I will link to a friend of mine who has dedicated his website to this fantastic language.
So if you want to start hacking Python, you might want to check out the code at CVX | code version x. All dedicated to the Python and the fantastic world of Unix. Right now he has a tutorial on creating RPM's in Python.
By the way, besides many Linux distributions, the software engineers at United Space Alliance uses Python for Rapid Application Development.