I've been pondering the importance of specifying vendor prefixes like 'webkit', 'moz', 'ms' or 'o' in modern CSS. It seems that Opera has switched to Webkit, meaning we may no longer need '-o-'. IE10 eliminated the need for '-ms-', but what about older versions? And as for '-moz-', the current status is a bit unclear.
All my CSS3 styles seem to be functioning smoothly on updated browsers without any prefixes, so I'm curious about what is essential and what isn't in mid-2014.
EDIT: I'm really just looking for an updated list of required prefixes and the conditions under which they are needed.