Learn more on the HotDraw webpage: http://st-www.cs.uiuc.edu/~brant/HotDraw
It includes pointers to several versions of HotDraw in different Smalltalk-80 dialects. But none of them will filein and work with Squeak. That's why HotDraw is now listed on ToolsAndGoodiesWanted.
It would be helpful if one of the Smalltalk-80 old-timers who know the pedigree of various ST implementations could point out which ones are closest to Squeak.