I’ve just launched my own custom Tumblr theme. I hand-crafted this Tumblr theme in TextMate using HTML5 and CSS3. I wanted a clean, simple theme written using semantic HTML5 markup. The markup and CSS should degrade gracefully in Internet Explorer (although I haven’t tested it just yet).

I hope to soon convert this Tumblr theme into a responsive web design so that it adapts appropriately to various clients such as iOS and Android mobile devices. Let me know what you think!