Microsoft late last week released an updated test version of Windows XP Service Pack 3 to about 15,000 beta testers. The update, the third such service pack for the six-year-old operating system is due out in final form in the first half of next year. The company said before its final release it expects to issue a public test version of the service pack, though it did not provide more specificity than at “a later date.”

A few months later than had been planned, Mozilla released on Monday night the first beta version of an overhauled Firefox, the widely used open-source Web browser.

Firefox 3 beta 1 includes a number of significant features that Mozilla said should improve security, ease of use, rendering of Web pages, and location of previously visited Web pages. And for the new era of rich Internet applications, the browser can run Web-based applications even when the computer is disconnected from a network.

The software is available for Windows, Mac OS X, and Linux at Mozilla’s download site in 20 different languages.