great program, 2 minutes to download and install, easy to use with my 6 year old brother, graphics arent very good, but it not ugly.
John W.(7/6/2006 - version 1.6.680)
Version 1.6 appears to be incompatible with just about any Mac running OS 10.3.9 -- no, you can't find the "upgrade" to the sound card referenced in the FAQ -- and you can't download the earlier versions of LDD (which did work on older Macs).
Mr. Cube(12/27/2005 - version 1.4)
Version 1.3 was the best one because after that the program was changed to allow you to purchase your model. While that was a good idea, you now have to pick which "sets" you want to build your model from. You can no longer build with select infinite pieces.