Since 2014 we've added support for all the recent browser versions and we still support the older ones from back then.
We recommend you use the latest stable release of the respective browser as we focus our QA efforts on that. Most browsers have auto update these days.
Supported browsers for the cockpit:
Google Chrome: 17.0.963.56 +
Mozilla Firefox: 3.6 +
Microsoft Internet Explorer 9 +
Apple Safari: 5 +