There was a nice extension called DivaScheme that used unchorded keystrokes like vi and allowed structural editing but it stopped working when PLT Scheme reache

There was a nice extension called DivaScheme that used unchorded keystrokes like vi and allowed structural editing but it stopped working when PLT Scheme reached version 5. (Which I think was when they changed the name to Racket.) https://cs.brown.edu/research/plt/software/divascheme/ https://cs.brown.edu/research/plt/software/divascheme/