While Chris Wilson, Platform Architect of the Internet Explorer Platform team at Microsoft, is just about getting ready to offer a general preview of the plans for Internet Explorer 8 at MIX07, Mozilla has made available for download yet another milestone of Firefox 3.0. The new version of the open source, which is right on track for general availability in the second half of 2007, has now reached the Alpha 4 stage.

"Gran Paradiso Alpha 4 is an early developer milestone for the next major version of Firefox that is being built on top of the next generation of Mozilla's layout engine, Gecko 1.9. Gran Paradiso Alpha 4 is being made available for testing purposes only, and is intended for web application developers and our testing community. Current users of Mozilla Firefox should not use Gran Paradiso Alpha 4," reads a fragment of the Gran Paradiso Alpha 4's release notes.

Building on the development changes introduced by the three previous builds of Gran Paradiso, the Alpha 4 refresh brings to the table a set of new features designed for testing. Most important, Mozilla has informed that the new modifications in this Alpha version of Gecko 1.9 impact directly the web and platform compatibility of Gran Paradiso Alpha 4. Additionally, the new release focuses on the following features:

- Inclusion of the FUEL Javascript library for extension developers
- New Page Info window
- Many Cocoa user interface improvements and bug fixes
- Basic Mac OS X crash reporting via Breakpad
- Improvements to offline application support. Enabled Listing of Offline Resources and implemented SQL device for the offline cache
- Miscellaneous Gecko 1.9 bug fixes

Mozilla Firefox 3.0 Alpha 4 / 2.0.0.3 was tested by Softpedia as being 100% Free and is available for download here.