[texel]

To my knowledge, XMLHttpRequest Level 2 isn't supported in any shipping version of IE. I haven't tried IE9 yet, so it might be available there. When building the actual production uploader for onehub.com, I drew a line in the sand and decided not to support any fallback scenarios, at least for the first iteration. If you'd like, fork the uploader on github and hack away :)

[steveklabnik]

Thanks. I just might, next time I need to do file uploads... I've been really enamored with Sinatra as of late, and it seems like every side project I do needs file uploading...