A few days after the Opera 10.50 beta for Windows got its second revision, the first Mac beta for version 10.50 finally has been released to the public. There has been a pre-alpha release available since late December, but it hasn't received the multiple public upgrades that the Windows one had, until now.
In casual testing comparing Opera 10.50 beta 1 to Google Chrome 5.0.335.0 on a Mac Mini with OS X 10.6 Snow Leopard, a 1.83 Ghz Core 2 Duo processor, and 1 GB of RAM, the development version of Google Chrome was slightly faster than the new Opera beta. Opera scored an average of 598.33 milliseconds over three runs, while Chrome notched 562.53 ms averaged over three runs. Regardless of which one is actually faster, these improvements are just as dramatic as the ones made to the new Opera beta on Windows and indicate the Opera is taking progress seriously on both Windows and Macs.
Other changes include the browser being built from the ground up in Cocoa, Growl and multitouch support, support for the HTML5 < video > tag, and extensive hooks between Opera Widgets and the desktop. This means that widgets can be used as standalone apps, previously limited to the Windows version. Opera Unite also works in this beta, and there have been extensive interface tweaks--though nothing as dramatic as the Windows 7 changes. The new beta also supports OS X 10.4 Tiger, although the browser won't work on PowerPC chips for now.
The full changelog can be read here.