Smalltalk history - draft 2

Ok, here's another draft of my diagram of Smalltalk History. 

Smalltalk history

As part of a new Introduction to Smalltalk course I'm developing to be delivered as an online course, I've put together a brief history of Smalltalk. I think it's important to know where the different dialects of Smalltalk came from.  I'll likely release this video for free.

Part of the video is the following diagram of the companies involved in the major Smalltalk dialects we see today.