24 January 2014 at 5:38am
"SilverStripe CMS is designed to work well with Firefox 3.0+ and Internet Explorer 7.0+. We aim to provide satisfactory experiences in Apple Safari and Google Chrome. SilverStripe CMS works well across Windows, Linux, and Mac operating systems."
This is slightly out-of-date, though, IE7 is no longer supported in the CMS.