1. Subscription. I'd pay for a one time license. I'd pay for upgrades, but I'd want to own it.

I'd love to have this, but as latchkey says for a one-time purchase. Ideally, the app would be open source and available for Mac as well as Linux, so one could add bespoke extensions. Note the reason I say "open source" is not because I would want it for free, but because open source means I will still be able to use it in 20 years on whatever platform will be mine then.

Wish list:

- plug-in for Emacs, Atom and Sublime.

- versioning support (Git integration)