Mozilla 101

The background:

The first web browser that worked on Macs and PCs was called Mosaic, developed by Marc Andreesen at the National Center for Supercomputing Applications (NCSA) at the University of Illinois-Urbana. This was back in 1993, when Internet apps were mainly developed academically instead of commercially.

The next year, Andresssen and a venture capitalist, Jim Clark, founded Mosaic Communications to develop and market the browser and other net-based software. In development, the browser was called Mozilla, a combination of Mosaic and Godzilla. The final product name was Netscape, but the old name stuck; the website was adorned with a cartoon version of Mozilla, and the installation file even told the user, "It's spelled Netscape, but it's pronounced "Mozilla." Mosaic was sued by the NCSA over use of the Mosaic name; it changed its name in late '94 to Netscape, and later renamed the browser Navigator.

The point:

In the initial commmuncation with web servers before downloading a page, Navigator still identified itself as Mozilla. In 1995, Microsoft bought a Mosaic clone from Spyglass and fashioned it into Internet Explorer. The problem for Microsoft is that Netscape had programmed a lot of tricks into its browser that weren't part of the WWW specification. These extra page features weren't given to MS's browser unless it identified itself as Netscape, or rather, Mozilla. So MS fudged the identification, by sending something like this to the server:

It's essentially saying that it's Mozilla 4.0 compatible, then admitting in parens (which old-school servers ignored) which version of Internet Explorer it actually was. Newer servers do pay attention to the IE version number, as well as that of the operating system (Windows NT 5.0 = Windows 2000).

The confusion:

Things got more complicated a while ago: Netscape 4 was the current version, and version 5 was stalled in development. As a Hail Mary, Andreessen bet that the free, collaborative development model of Open Source could do a better job of producing a fast, stable browser. The project needed a name that was familiar, but not already someone else's trademark, so they used 'Mozilla.'

Netscape ill-advisedly ended up betting too much of the farm on Mozilla: it scrapped development on Netscape 5 altogether. Unfortunately, the Mozilla project took years longer than expected to produce a usable browser, which is why many systems out there are stuck with the ancient Netscape 4, whose long-outdated and buggy support for newer web standards is the daily bane of web designers everywhere.

The Mozilla project releases versions of its browser, called Mozilla, on a regular, sometimes nightly basis. As the browser progresses, versions are taken by AOL from time to time, given more marketing polish, and rebranded as Netscape 6 (now 6.2). Some people use Mozilla instead, given that new features and bug fixes appear more quickly due to its more frequent release schedule.

Since Mozilla is now the actual product name of a browser in use, it's easy to assume that it's being used when the name shows up in an error message. But that's simply not the case: every current browser, one way or another, is a descendant of Mozilla, and tips its hat to the server accordingly.