Since last week's announcement of the YouTube and Vimeo beta versions which use HTML5's element, the Mozilla developers have been defending the fact that Firefox 3.6 cannot play the content on these betas even though it supports HTML5. The reason for the problem is that the HTML5 working groups decided not to specify which video codecs the tag would support. The h264 standard, which is patented and licensed, has already been invested in by Google's YouTube and Vimeo to encode videos and Google's Chrome and Apple's Safari both support the use of h264 as a codec for the element.