Cyberbrau is a web based program to help the homebrewer. CyberBrau project allows for very simple and intuitive recipe creation, and it automatically calulates all the pertinant information based on the selected ingredients and schedule.
In addition to the recipes, it allows the brewer to track their batches, making note of racking, bottling and lagering time frames.
Finally, it has a 'taster's review' section which allows those who try your brew to rate and comment on the batch. This information goes into the overall recipe ranking.
Cyberbrau uses PHP 4 and MySQL. It has never really been tested on anything but linux, but there is no reason why it shouldn't work on anything that the above runs on.