The creators of deviantART have embraced HTML5 within their new drawing application which uses the canvas element and allows their users to produce artwork in their browser.
Comments from the Authors:
From start to finish, deviantART Muro allows users to create complete works of art in ways never before realized by digital drawing programs. deviantART Muro already boosts standard and interactive brushes, full-blown layer capabilities, and the ability to upload directly to your deviantART account, but we’ve also left room for expansion. You can expect to see many features and functions added in the coming weeks and months.