The Omni Group has released a public beta of the next version of their OmniWeb browser. Version 5.5 brings some much needed changes to OmniWeb, most notably the switch from the aging WebCore engine to a recent build of WebKit. I have participated in the private beta of 5.5, and its stable enough for me to use as my main browser. Keep in mind however that this is beta software, and crashes will be par for the course. For better or for worse, though in my opinion for the worse, The Omni Group decided to mark up the menu-bar of the beta with a hazard stripe pattern. I understand that they want users to know they are using beta software, but if someone is going to go to the trouble of downloading and installing the beta, they probably know the risks involved. Additionally, the beta will only run for 15 days. Omni Group engineers have assured me that this is simply to ensure that people are using the most recent builds of the beta as they are released.
Update: Josue points out that the disk image for the beta requires a password that can only be found at the Omni Group Forums