One of the worlds most used mobile web browsers is headed to Android devices. Opera Mobile – the fully featured father of Opera Mini – will be free of charge.

Opera Mobile uses the presto layout engine, coupled with Opera’s Small Screen Rendering technology which dynamically reformats web pages for small screened devices.

There is no release date yet, but users can already download Opera Mini for Android today. Opera Mini is already installed on over 71 million hand held devices.

Below is a video demonstration of Opera Mobile which was shown over at TechCrunch.

Android users prayers have been answered, with the release of Opera Mini 5.1 final for Android devices.

“Since the beta, Opera Mini has improved rendering to make browsing look better on high-resolution devices. Text is legible even when zoomed out. In addition to your favorite features such as tabs, Speed Dial navigation and Opera Link, surfing with Opera Mini is smother with improved kinetic scrolling” wrote Opera’s Aleksander Aas.

The browser can also be set as the default for the device, and full screen will now utilise the whole display.

Opera Mini is available in 92 languages, and can be downloaded from the Android Marketplace or directly from m.opera.com.

Mozilla have released a pre-alpha build of it’s popular Firefox browser for Android devices. The browser, previously known under the Fennec codename, has been released to gather feedback from the Android community.

This news comes just a month after Mozilla announced it was putting Windows Mobile development on hold, and shows there is still life in the mobile version of Firefox outside of Windows Mobile and Nokia Maemo devices.

So far, the browser is only confirmed to be working on the Motorola Droid and Google Nexus One at this early stage of development.

Vladimir Vukićević has stated that this early build has poor memory management, and this build requires Android 2.0 or above, and likely an OpenGL ES 2.0 capable device. This is on top of a few other smaller issues.

Firefox for Android can be downloaded from http://bit.ly/fennec-android.