Digital photo processing software, as opposed to Darkroom I suppose
They have just released a Beta version for Windows, free to to use until Jan 2007.
Needs at least XP sp2
If you have Photoshop and a few plugins probably not much use, could be a cheaper alternative to PS.
http://labs.adobe.com/technologies/lightroom/
You have to register to download, the full download with samples and tutorial is over 100MB, there is a base version of about 7.5mb.