Customisable WebParts type interface in Rails?

Hello all,

I have been tasked with creating a web front end that is composed of
relatively independent block of functionality, much like ASP.NET’s web
parts or Google gadgets on the iGoogle page. The blocks should be easy
to re-arrange (either statically or dynamically) and it should be
simple to add new blocks. My question is whether there is a good
infrastructure in Rails to easily construct and support such a web

Thanks for any advice,