Even if we didn't go that far, I'd be happy if Congress started using open source practices/tools just so things are easier for the public to audit and follow. Bill's text in public throughout the whole process. Public and documented changes/proposals/comments even if still made by only members of Congress.

And a single official repository of all laws that can be edited directly and kept up to date. The United States Code is actually a pretty good place to start, here I’m just suggesting modernizing it.