Sun Distinguished Scientist James Gosling (of emacs fame) has been working for several months on an SGML editor called "Imagination" using C++. Gosling gets thoroughly frustrated with C++.
The Oak language (now Java) grew out of Gosling's frustration with C++ on his "Imagination" project. Gosling claims that he named Oak when he looked out his window and saw a tree. However early Sun papers refer to Oak as the "Object Architecture Kernel." It is unknown whether the name or the acronym came first. In either case the Oak name did not survive a trademark search and was changed to Java in 1995.
Naughton discovers NeXT, and decides to leave Sun to go to work at NeXT. He tells Sun CEO Scott McNealy about over beer after a hockey game. McNealy asks him to write a letter about what he thinks is wrong with Sun. Since he's leaving anyway, Naughton writes an extremely negative email about NeWS and Sun's entire culture.
Naughton's email is forwarded around the company, to a chorus of "That's what I thought, but I didn't want to say so." (After all, not everyone was planning to leave Sun the next day.) In particular, Bill Joy and James Gosling felt similarly.
To keep Naughton, Sun made him a counter-offer. He would be allowed to create a small team of engineers outside of mainstream Sun in order to "do fewer things better."
Thus Patrick Naughton started the Green Project on December 5th, 1990. That month he recruits Gosling and Mike Sheridan to help start the project. Bill Joy shows them his Further paper. and work begins on graphics and user interface issues for several months in C.