I want other people to be able to learn from and build TrailNAV, so I will share it openly. My plan is to keep all the documentation and the design files on my Fab Academy page, write a short build guide, and post about it so other makers and outdoor users can find it. Sharing openly fits the spirit of a Fab Lab, where the work is meant to be passed on.
I chose an open licence so anyone can use, change and build on my work as long as they give credit. For the documentation and the design files I use a Creative Commons licence, and for the code I use an open source licence such as MIT. I picked these because they let people learn from TrailNAV freely while still asking them to mention where it came from.
Right now TrailNAV is a working prototype. The next steps that would turn it into something real are to make the board smaller and cheaper, to test it with hikers on a real trail, and to find out if anyone would pay for it. To make these likely and not just possible, I would build a few more units, give them to people to try, and use their feedback to improve the design.