Intellicad(similar to autocad) for Linux, there are a couple, the best I found was Bricscad.http://www.bricscad.com/
. Does cost, not that much compared to autocad though.
Also you can get Progecad Smart (free for persoanl use-adds a note when printing) and run it with wine.
I use intellicad, but Qcad is quite good for smaller projects,well woth paying the 35euros for the full version (you get polylines) although the community version is good.