The full and latest source is always available under https://github.com/TomyLobo/routes

The plugin is still in development, but there is a routes-preview.jar in GitHub's download section. Usage:

1. Add a route with /ro[utes] add
2. Get a golden spade and right-click with it where you want waypoints
3. Optionally test the route use /travel test . That will make a (fake) dragon go on the route
4. When done, put a sign somewhere (ideally near the start of the route). Any line containing "@@" will be interpreted as a route entry.
5. Get an arrow item
6. To use the route, double-rightclick the entry on the sign with the arrow in your hand

The current version is released under LGPL. If I add an API, I'll probably switch to GPL (with linking exception for CraftBukkit and unrelated plugins).

If you want to help with development, send me a PM. If I don't know your work, make sure you include a link to it so I can see if you've got the skills it takes.