Yes, open source sounds like the right place for ideas like this, for the reasons you mention. Consider Emacs, whose hundreds of extensions give you this mix-a

Yes, open source sounds like the right place for ideas like this, for the reasons you mention. Consider Emacs, whose hundreds of extensions give you this mix-and-match setup, or something similar to it. I think I might really like working with a system that works in this way, with a bit from here, a bit from there -- but I'd want access to the code, because it would take a lot of tweaking to make things nice.