In 1978 the Smalltalk group at Xerox tried to build a computer that people could buy. The Notetaker used several 8086 processors in a sewing machine form factor

In 1978 the Smalltalk group at Xerox tried to build a computer that people could buy. The Notetaker used several 8086 processors in a sewing machine form factor (like the later Osborn I) so you could carry around a computer with floppy disks, a mouse and windows. An executive came from the headquarters specifically to kill the project because Xerox didn't want to sell microcomputers. Frustrated, the group got permission to license the language to run on other people's computers. All the other companies would have to do would be to implement their own version of the virtual machine and the rest of the system would just work. They made a deal with Apple, HP, Tektronix and DEC where these companies would get the language in exchange for having a small team help Xerox clean up the system and the draft of a book about the system by trying to do their own implementations. This was eventually published with the title "Smalltalk-80: The Language and its Implementation" and became known as the blue book since that was the main color on the cover. It had four parts: 1) an explanation about the language and its concepts 2) a reference for all the classes and methods in the system 3) a large example in the form of a discreet event simulator 4) the definition of the virtual machine in the form of explanations and Smalltalk-80 code written in a style that could easily be translated to Pascal or C Years later a version without the fourth part was released with a purple cover. Before the book came out, a series of articles about Smalltalk-80 were published in the August 1981 issue of Byte magazine. Another book was "Smalltalk-80: The Interactive Programming Environment" about the GUI. It became known as the orange book. There was another book that was planned but never released. As part of the efforts of the implementation groups (now 5 since DEC shared its license with Berkeley) they had some mini conferences to share experiences and decided it would be great to make that into a book as well. "Smalltalk-80: Bits of History, Words of Advice" was the result and became known as the green book.