Caja compiles Javascript into different javascript, allowing you to put untrusted gadgets in trusted container pages (eg OpenSocial). Removes potentially evil code (eval etc), and passes in an object representing the global scope (document etc).
Ben’s writing a Caja wrapper for OpenSocial. Lots of hairy stuff with closures wrapping callbacks in functions, then wrapping the response in more functions. I haven’t really looked at OpenSocial yet, so some of this is flying merrily over my head.
[tags]barcamplondon3, caja, opensocial, javascript, gadgets[/tags]