Ask HN: GIS - offline routing with javascript?

I want to build an GIS application (HTML5/JS) with abilities to do some routing while the used device is offline.

Dijkstra and A* should be enough in this case, but I would like to know if there is already a offline library for this particular task, I don't want to reinvent the wheel. I've thought of a adjacency list using JSON.

There are some routing services out there, but every service requires a server connection to calculate the routes. It would be cool if there is something like a OSM-XML (cached) routing library for OSM data, but I didn't see JavaScript libraries for that.

Thank you for your advice.