Hmm.. I think i am getting old.
Here are some good articles
1) Ref: http://www.cs.cf.ac.uk/Dave/X_lecture/X_book_caller/
2) Ref: http://www.sitepoint.com/article/real-history-gui
The start of the development of GUIs can be traced back to the early
1970's to Alan Kay's research group at Xerox's Palo Alto Research
Centre. Two important projects were undertaken there:
* Dynabook (Early 1970s) -- where the goal was to produce a book
sized personal computer with high resolution colour display and a radio
link to a worldwide computer network. Mailbox, library, telephone and
secretarial functions were also to be incorporated.
* Star (Late 1970s) where the goal was to produce a desk-sized
personal workstation used by a single person. A high resolution display
capable of fast high quality graphics was included. Graphical user
interaction was provided by means of a mouse allowing options to be
selected from a displayed menu . Later versions of Star introduced icons
on the screen to represent objects and functions. The idea of traits --
a characteristic of an object that can be expressed by a set of methods
or data and can be applied to, or carried by, the object holding that
trait -- was also introduced. Traits were later to resurface in last
release of Motif (2.0) (Chapter 21).
The first commercial exploitation of the Xerox work was realised in the
early 1980s by Apple, firstly with Lisa and then the Macintosh series of
computers. The Apple GUI proved very successful and popular and by the
late 1980s many operating systems had adopted the GUI approach. UNIX
vendors such as Sun (with SunView) and Dec (with DEC Windows) and
Microsoft with Windows for the PC are examples.
And the history of unix is here. Best. http://www.levenez.com/unix/