Posted by brandonthedeveloper at June 3rd, 2009

From the BrowserLab homepage:

BrowserLab provides web designers exact renderings of their web pages in multiple browsers and operating systems, on demand. BrowserLab is a powerful solution for cross-browser compatibility testing, featuring multiple viewing and comparison tools, as well as customizable preferences. Since BrowserLab is an online service, it can be accessed from virtually any computer connected to the web. Also, Adobe Dreamweaver® CS4 software users have access to additional functionality such as testing local and active content.

Limited Free Preview
The BrowserLab free preview is available to a limited number of users, while we monitor its performance. Please visit our service status page for updates.

Browser renderings can be viewed alone, side by side or ‘Onion Skinned’ (on top of each other with an adjustable alpha transparency).

Currently, the test OS/browser combinations are limited to Windows XP – IE6,7, FF2,3 and OS X Safari 3, FF 2,3.

See the BrowserLab homepage for more info.
Try BrowserLab.