Few weeks ago Alien Skin announced a new non-destructive editing software called Exposure X that will not be using a catalog file. The official announcement will be by the end of the year.
Additional information:
Exposure X doesn’t have a catalog file. That makes many things easy, such as rapidly browsing photos. You don’t need to import photos into Exposure X. Just visit a folder and get to work. Exposure X can quickly organize photos like Photo Mechanic or Bridge, but it can also non-destructively edit them like Lightroom.
Exposure X stores the edits for each photo in the same folder where it lives. That makes it easy to take the folder on the road or back it up. Just move or copy the whole folder and you’ll have the photos along with their edits, star ratings, flags, etc. You can even use a cloud storage service like Dropbox to work on the same photos from multiple computers.
Via Alien Skin blog