OK, so Firefox 3.5 is out and looking good but why should Opera care? After all, the alternative web browser from years back has long since lost that title to Firefox, at least as far as the desktop is concerned. But what about in the mobile market? Opera has been making real progress in penetrating the mobile device embedded browser market. It isn't Firefox 3.5 which should be worrying Opera but rather another Mozilla release: Fennec.

The Mozilla mobile browser has been released in Alpha form for Windows Mobile, as well as a Beta for Maemo (Nokia's software and development platform) although the two share the same code base. According to Stuart Parmenter, Mozilla’s mobile team technical lead, it has been working on "improving the user experience, replacing our old theme with a much nicer looking one and fixing numerous usability issues. We’ve continued to increase performance and responsiveness. We’ve revamped how you install Add-ons, improved our download manager and the whole look of the application. We’ve started work on making forms on web pages easier to use, providing a nicer combo box UI than before."

Fennec is also already starting to get some add-ons built by the developer community which take advantage of new location aware APIs to bring mapping and information to where the user is, as well as things such as a Twitter client which adds the ability to post drawings as tweets.

Although it is early days yet, the idea of Mozilla taking the mobile market seriously will have to be a concern for Opera.