Appendix B: VMS and the Web


By Alan Winston

In a way, this chapter also answers the question "Why VMS?" A short answer is "Because it was there from the start."

Beginnings

As you may well recall, Tim Bernars-Lee at CERN, the European high- energy physics laboratory, invented the Web as a convenient means of sharing high-energy physics information stored in different forms on diverse servers. VMS systems were big players in the scientific community. (They'd been preeminent in the middle 1980s, but the price/performance of RISC-based UNIX workstations compared with that of the VAXes, which were the only VMS platform at the time, meant that the price-sensitive and performance-hungry scientific market was buying a lot of those as well.) So CERN developed Web servers for UNIX, for IBM machines, and for VMS.

The Web uses the HyperText Transfer Protocol (HTTP), so a typical name for a Web server is HTTPd, with the "d" standing for "daemon." (A "daemon"—an essential concept on UNIX systems—is a program that runs in the background, listening until it recognizes that it needs to do something, then doing it.) The first HTTPd was developed at CERN; and the first non-European Web server was installed at SLAC [1] in December 1991 (running on an IBM mainframe). My site started running the CERN HTTP server on VMS in 1993 (on a VAX 8700).

A basic Web server, one that just takes requests and serves files, isn't that hard to write. The requirements begin to get exponentially more complicated when the server needs to provide dynamic content in various ways; when it needs to support encrypted communication; when it needs to handle heavy loads gracefully; and when it needs to be robust and secure in the face of hacking attempts and badly behaved browser software. The Web actually started before the Internet went commercial, and the environment for Web servers changed considerably when that happened.

CERN eventually needed to spend its money on the Large Hadron Collider and ceased WWW software development after December 1994. (The CERN server can still be found on the OpenVMS Freeware CD.) Various computer science and physics sites had already developed browsers, including SLAC; the National Center for Supercomputing Applications had already developed Mosaic (whose developers went on to found Netscape) and produced an NCSA HTTPd; but development on that product stopped when the primary author, Rob McCool, left. NCSA HTTPd was the most popular server on the Web, but Webmasters now had to develop their own patches, changes, fixes, and enhancements without any coordination, and the program was wandering in different directions.

[1]www.slac.stanford.edu




Getting Started with OpenVMS System Management
Getting Started with OpenVMS System Management (HP Technologies)
ISBN: 1555582818
EAN: 2147483647
Year: 2004
Pages: 130
Authors: David Miller

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