The next version of the Firefox Web browser – called Firefox 1.5 – is due for release later this summer. Development is ongoing, and the update promises an automatic update service.

Chris Hofmann, lead engineer at The Mozilla Foundation, open-source group that oversees the Firefox project, said on Friday that contrary to news reports, the release hasn’t been delayed.

“There really hasn’t been any official date [for a release]”, Hofmann said. According to Hofmann, the target time-frame for a new release has always been mid- to late summer

So far, developers are making good progress in adding features to the upcoming version of Firefox, including development features that can be used to encourage additional Web applications for the browser, Hofmann said.

First and second alpha releases of the application were released last month, and a beta version is expected soon. But no specific date has been offered for when the beta will be available.

Earlier this week, The Mozilla Foundation announced that international versions of Firefox and the Thunderbird email client would be delayed so that several recent security fixes could be included. The delay arose from a number of software glitches introduced in last week’s release of English-language versions of Firefox and Thunderbird.

The open-source browser emerged in November as a free download, and has grown as a popular alternative to Microsoft’s Internet Explorer browser and other competing browsers.

By April, Firefox had been downloaded 50 million times, according to The Mozilla Foundation.