There is currently Tern support for the following editors:
Follow the links to find instructions on how to install the plugins.
There are two mailing lists for the project, a low-volume one for announcements at tern-announce, and an open one where everyone can post at tern-dev. For reporting bugs, I prefer that you use the github issue tracker.
Code contributions are welcome, preferably through pull requests.
The maintainer of the project (Marijn Haverbeke) is, in principle, available for consulting work around Tern. Commercial support contracts are also possible. Contact me for details.
The reference manual should be your first stop for figuring out how to use Tern.
If you are interested in the way the system works internally, take a look at this blog post.
03-05-2013: Version 0.1
First numbered release. Should be considered beta status, but useable enough to test.