Gunstruction AR15 builder
http://www.ar15.com/gunstruction/
did a quick search on here and this didn't seem to pop up, seems like a neat ar15 building aid thats fully 3d. the depth of parts that you can change out is pretty impressive and even offers you the ability to previs your paint/colour scheme. doesn't have everything obviously but still pretty cool. please forgive if this has been posted before