Volunteers can use just about any browser commercially available that supports javascript, including browsers on many mobile devices like the iPhone, Android and recent versions of Blackberry.  For administration of ivolunteer.com, we recommend using current versions of Chrome, Firefox, or Internet Explorer 9 or 10.  Google Chrome is our browser of choice and performs extremely well with large events. Chrome can be downloaded here. Internet Explorer 8 and older are NOT supported for administration of events needing more than about 1,000 volunteers.