If they are RDS files, they'll have an extension like RD3 or RD4. I don't know of any programme other than RDS which will open Raydream Studio files. Raydream is fun (I've just got the programme about 1 week ago and am still learning). It works quite differently to MAX, and produces excellent organic shapes as well as very good "raditional" 3D objects. You might like to ask this question again in the Raydream/Carrera Forum to get a little more in depth reply. If you know anyone who has RDS, they can convert the files to OBJ or 3DS format for you. If all else fails, drop me a line Paul