E-peen tiem

What's the best program you've ever made?
Both in terms of quality and complexity.
Personally, I've made a basic cli calculator with some trigonometric functions included.

A small Windows program for entering of order related data, and drawings and documents and stuff for automated generation of O.A. mails and printing of documents for documentation to customers. And also generating of CD interface, to save on environment and money.

It's used daily by over 20 persons.

Biggest crap ewer :D, but it works and that whats counts sometimes. Desperately in need of a real EIM strategy.