Adobe is offering a bèta download for Lightroom 2.0, Adobe's tool that competes with Aperture.
This new version brings many improvements, and even supports 64-bit architecture on OS X -it's the first time that Adobe uses OS X' 64-bit features.
You can test the bèta for free for 30 days, and existing Lightroom 1.x users can use it untill August 31, 2008. The beta can be used together with an exisiting Lightroom installation.
There's also still an 1.4 update in the pipeline, expected somewhere in April.
https://www.adobe.com/
[translation by xavier]