Hewlett-Packard has recommended that users of America Online Netscape browser erase it from their hard drives to avoid the growing list of "potential" vulnerabilities allowing denials of service, information leaks, unauthorised access and remote malicious code execution.
HP said it will no longer support Netscape for its HP-UX version of Unix, and urged users to switch to Mozilla, the open-source project on which Netscape is based.
The Mozilla project was founded in 1998 in order to take advantage of the open-source development model, in which developers have access to software source code and are free to use it to create derivative products. Netscape hoped the project would spur faster development, but it was 32 months before a commercial browser emerged.
In the meantime, Internet Explorer took over the browser market - benefiting from Microsoft's dominance of the desktop rather than from better technology.
Last year, Time Warner's AOL subsidiary distanced itself from the browser it inherited from Netscape, first signing a seven-year deal to continue using Explorer, and then spinning off Mozilla into a non-profit organisation.
On Windows, years of Explorer dominance have made switching away from the browser all the more difficult, according to industry analysts.
Explorer is very popular, it is used by about nine in 10 web users. This has made it the target of ever-more-sophisticated attacks, security experts claimed.
On other platforms, such as Linux, Unix and the Mac, Explorer is less of a threat.
Microsoft said it would scale back Explorer development for the Mac after Apple introduced its own Safari browser, based on the open-source KHTML rendering engine. Microsoft does not make a version of Explorer for Linux or Unix, where Opera Software ASA's browser or those based on KHTML or Mozilla are the norm.
Opera is the only browser that claims to run on Windows, the Mac OS and Unix-like operating systems; a stripped-down version also runs on Symbian OS, embedded Linux and other mobile devices.
Opera admits its browser suffers from the same compatibility problems that plague other Explorer competitors, but argued that the problem is naturally on its way out.
"With the advent of the wireless internet, webmasters must start complying to W3C standards, or else their pages will not be accessible to the majority of the internet population," the company said.
"The two dominant browsers on the PC are too bloated to fit into small, handheld devices."
Matthew Broersma writes for Techworld.com