One of the more unique programming approaches I've come across is the Leo editor, which was written to support literate programming but also functions as an out

One of the more unique programming approaches I've come across is the Leo editor, which was written to support literate programming but also functions as an outliner. When you're working with Leo, you work with a tree of text nodes instead of working with explicit files/directories. Because the nodes exist in an always visible tree, the natural inclination is to label the node with what the code inside does. This subtly enforces literate programming. This is good, but what makes Leo novel is the nodes can be cloned (think hard symlink) and then rearranged however you like. You can put a node containing a function's unit tests and another containing its documentation as children of the node containing the function. When fixing a bug, you can create a node that points to the issue's url in your bug tracker and then clone all related nodes as children for both documentation and convenience when you're working on the bug. When working on frontend code, you can clone nodes for related js/html/css for conveniently switching between them. It's very cool. Unfortunately, it's not really practical to use it as your primary editor. Ed serializes/deserializes the nodes to files using sentinels in comments, so the output files tend to wind up with a lot of "junk" comments. I also missed the Vim command grammar a lot.