How to represent formatted text for display on IPhone/Android/WP7/PC

I am working on a multi-platform app (Mono) that will store text in a centralized location on the web and synchronize this text across clients that could potentially be IPhone/Android/WP7/OSX/Windows(WPF)/Linux/Web. I need to support some degree of rich text (at minimum bold/italic/etc./basic lists/alignment), and I am trying to find a format that will be easil开发者_如何学Goy displayable and editable across all these platforms (though I'm using Mono, the GUI will be implemented with the native toolkit for each platform), so far I can only think of HTML or RTF, neither of which sound very pleasant.

Thanks!

---

Thought I'd answer this for completion. Eventually I ended up going with html, since every platform has an embeddable browser control for display, and for editing - WPF has richtextbox which, though a very very unpleasant exercise, can be used to edit and produce html. Mac has NSTextView, which is a much nicer way to edit and produce html. And on mobile, rich text is not yet feasible for editing so its just a question of plain text wrapped in

...etc.