Sympathy is an in-browser text editor for Chrome, which allows you to edit local files. This means you
can browse to
file:///path/to/file.js and it will open in Sympathy itself and you can save/edit it
within Chrome itself.
Sympathy does not hit the web for any sort of sync ever. It is an alternative to simple text editors such as geany/notepad++, but it works within your browser.
Because the future is the browser? And more so because I wanted a local editor in my browser to complement a terminal. Other than these three things, what more would you need? You can read the related blog post at my blog which gave birth to this editor. I was initially hoping for a chromium fork as I could not think of a way to get (good) local file access in chromium, but I recently heard about NPAPI plugins having full access to local filesystem (and consequentially npapi-file-io).
Sympathy does not use the HTML5 filesystem API. It instead relies on a NPAPI plugin called npapi-file-io. The plugin acts as a relay between the frontend and the filesystem, allowing you to save and read files, directories.
A move to use backbone.js is in progress (see the backbone branch). Lots of exciting features are planned as well.
It only works with Linux/Windows as of now. But due to lac of npapi-file-io bindings for mac, it won't work there.
I have not yet decided on the licence, but it will probably be MIT/GPLv3.