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Network Operating Systems-I

notes The project solved this by creating a protocol that could both run local applications and call on
remote resources. In mid-1983 an initial port of W to Unix ran at one-fifth of its speed under V; in
May 1984, Scheifler replaced the synchronous protocol of W with an asynchronous protocol and
the display lists with immediate mode graphics to make X version 1. X became the first windowing
system environment to offer true hardware-independence and vendor-independence.
Scheifler, Gettys and Ron Newman set to work and X progressed rapidly. They released Version
6 in January 1985. DEC, then preparing to release its first Ultrix workstation, judged X the only
windowing system likely to become available in time. DEC engineers ported X6 to DEC’s QVSS
display on MicroVAX.
In the second quarter of 1985 X acquired color support to function in the DEC VAXstation-II/
GPX, forming what became version 9.

A group at Brown University ported version 9 to the IBM RT/PC, but problems with reading
unaligned data on the RT forced an incompatible protocol change, leading to version 10 in late
1985. By 1986, outside organizations had started asking for X. The release of X10R2 took place
in January 1986; that of X10R3 in February 1986. Although MIT had licensed X6 to some outside
groups for a fee, it decided at this time to license X10R3 and future versions under what became
known as the MIT License, intending to popularize X further and in return, hoping that many
more applications would become available. X10R3 became the first version to achieve wide
deployment, with both DEC and Hewlett-Packard releasing products based on it. Other groups
ported X10 to Apollo and to Sun workstations and even to the IBM PC/AT. Demonstrations of
the first commercial application for X (a mechanical computer-aided engineering system from
Cognition Inc. that ran on VAXes and displayed on PCs running an X server) took place at the
Autofact trade show at that time. The last version of X10, X10R4, appeared in December 1986.
Attempts were made to enable X servers as real-time collaboration devices, much as Virtual
Network Computing (VNC) would later allow a desktop to be shared. One such early effort was
Philip J. Gust’s SharedX tool.
Although X10 offered interesting and powerful functionality, it had become obvious that the X
protocol could use a more hardware-neutral redesign before it became too widely deployed; but
MIT alone would not have the resources available for such a complete redesign. As it happened,
DEC’s Western Software Laboratory found itself between projects with an experienced team.
Smokey Wallace of DEC WSL and Jim Gettys proposed that DEC WSL build X11 and make it
freely available under the same terms as X9 and X10. This process started in May 1986, with the
protocol finalized in August. Alpha-testing of the software started in February 1987, beta-testing
in May; the release of X11 finally occurred on September 15, 1987.

Note X11 protocol design, led by Scheifler, was extensively discussed on open mailing
lists on the nascent Internet that were bridged to USENET newsgroups. Gettys moved to
California to help lead the X11 development work at WSL from DEC’s Systems Research
Center, where Phil Karlton and Susan Angebrandt led the X11 sample server design and
implementation. X therefore represents one of the first very large-scale distributed free
software projects.

the mit x consortium and the x consortium, inc.

In 1987, with the success of X11 becoming apparent, MIT wished to relinquish the stewardship of
X, but at a June 1987 meeting with nine vendors, the vendors told MIT that they believed in the
need for a neutral party to keep X from fragmenting in the marketplace. In January 1988, the MIT
X Consortium formed as a non-profit vendor group, with Scheifler as director, to direct the future
development of X in a neutral atmosphere inclusive of commercial and educational interests. Jim

30 LoveLy professionaL university