Even as Microsoft gears up to release Internet Explorer 8, the developers behind the Firefox Web browser are experimenting with a new technology that sharpens the threat their browser software poses to Microsoft’s most valuable businesses. The new technology, dubbed TraceMonkey, promises to speed up Firefox’s ability to deliver complex applications.

The advertising industry is bracing for trouble from the next version of Microsoft’s Internet Explorer, details of which were announced today, because it will offer a feature that blocks some ads and other content from third-parties that shows up on Web pages.

Mozilla plans to drag Internet Explorer into the next generation of open web technologies without Microsoft’s help. Programmer Vladimir Vukićević has developed a working prototype of a plugin, based on Firefox code, that makes newly developed HTML features available in to IE users. However, the plugin remains a work in progress, and development is still at a somewhat early stage.