IBM's Decimal Arithmetic FAQ is an interesting read.

Coming from an AS/400 background, I'm used to having decimal arithmetic around (albeit somewhat limited in terms of functionality). It is mainly used to store monetary values. Using floating point to store monetary values sucks.

Python doesn't come with a fixed decimal type, but the FixedPoint class will probably make it into the standard library at some point.

Ollie Rutherfurd has a bunch of useful macros for jEdit on his site, most of them written in Jython.

Useful in themselves, but also good examples to get you started if you were to want to write some of your own macros for jEdit.