Entering the awards is meant to be straightforward. If you are not sure how to proceed get in touch with the organisers.

Aim to convey the broad significance and benefits of your nomination rather than the technical detail.

You can make any number of nominations. In fact don't assume someone has already put your favourite project forward: nominate it yourself.

"Open source" can be interpreted in its widest sense (ie it need not refer to specific licences), but will generally be taken to mean a technological system where open collaboration and innovation prevails.