by "best" I am imagining:- on a laptop, no need to ever be switching windows
- instant refresh  on save (or rerun with very low build time if env is CLI), with state maintained.
- 1-2 keypresses to access previous file.
- dialtone editor features like auto-format on save, etc.
- help/code suggestions integrated into editor (probably an area I'd be flexible on)don't care what language. I just want to see what kind of flowful creative programming experiences are out there to really maximize the connection and refind the joy of programming after a day of clunky corporate work ...