GlkOte is open-source software (under the MIT license).
GlkOte has been tested on Safari 3 through 5, Firefox 2 and up, MSIE 6 and up, Opera 9.5 and up, and Chrome 5 and up. It is currently usable on Mobile WebKit (iPhone, iPad, and Android) browsers, but awkward -- you have to keep reopening the keyboard.
Glk home page
Zarfhome (map) (down)