Open-source development group released its long-awaited Mozilla 1.0 Web browser suite yesterday, after four years of development.

Mozilla 1.0 includes a Web browser, an email reader, and a chat client – with a cross-platform toolkit for developing Internet-based applications, the group said. Mozilla’s first major public release comes a month after the group released the beta version of the software, Mozilla 1.0 Release Candidate 1 (RC1).

The release has been eagerly awaited by open-source fans, who claim that the new browser could give big-name rivals such as Microsoft’s Internet Explorer and Netscape a run for their money.

Netscape released the source-code for the Mozilla project in early 1998. Since then, thousands of programmers have worked on the job, incorporating features such as tabbed browsing, a chat client (dubbed ChatZilla), and the ability to turn off various JavaScript functions to reduce pop-up ads.

The browser software is powered by the Gecko layout engine, which enables the browser to work as well on mobile devices as it does on desktops, the group said.

Mozilla 1.0 is a cross-platform product supporting Windows, Linux, and Mac OS 8, 9, and OS X.