Mozilla.org has made available an early released of Chimera, a Cocoa enabled web browser. Chimera is a work in progress and is current at version 0.11, it brings together a UNIX based browser and a Cocoa UI. As Mozilla describes it on their Chimera Project Page:
This is the project page for Chimera, a new project aimed at delivering a best-of-breed browser on the OS X platform. Chimera uses Cocoazilla, a variant of Fizzilla that consists of a UNIX back end wed to a Cocoa front end.
The cross-platform UI will be replaced with native Cocoa widgetry (such as customizable toolbars and a drawer for the sidebar). The plan is to produce only a browser (no other apps!), and to keep the UI as simple and as clean as possible.
The developers also say on the projectis home page that this new version is 33% faster than the previous version. This early version may not even be considered a beta release, but for those interested, you can get more info and download Chimera version 0.11 at the Chimera Project Page.