Or maybe using new "Web Apps" feature like MacOS has to turn web app into desktop.
<https://wiki.triplescripts.org/wiki/NOT#Not_a_cloud_IDE>
The trick is to untangle the mental equivalence of runs-in-the-browser versus mobile code (code on demand) and/or cloud-thingy-accessed-via-thin-client, which are all orthogonal concepts. To often these get confused. But just like you give people a Java, Python, whatever bundle comprising an app that targets its associated runtime, you can give people a bundle to download and launch from their own computer where the $RUNTIME it's meant to be launched with is /usr/bin/firefox (or whatever).
(And no, this doesn't require browser support for unstable/experimental APIs like Chrome's newest proposed APIs for filesystem access. There are ways to get by with HTML5 stuff that's well-supported by every mainstream browser released in this decade.)
see also:
For pricing, SnapCode is free for individual use and will remain so. Perhaps there will be funding opportunities from large organizations or for embedding use cases to help provide for the continued health of the product and community.
The online version is working well in my testing.
There is a preview feature for using drop box and I'm looking into using local file system APIs, but its not really there yet.