I understand in the proprietary world that a project can die, and then all the assets can basically be thrown out never to be used again in anything (or reused if the company owning them decides to but I understand a lot of times they are just thrown out.)
On the other hand in the free software world, even if no one has worked on a game for years and years and the original developers are actually dead, it doesn't follow that the project can never be brought back, and assets, and even code can be reused.
So, what exactly distinguishes a "dead" project from a "live" one.
I have tried to come up with some guidelines that arn't always useful.
Projects that have no commits within a certain time frame and have no active forum community where one can receive help are dead.
Live projects have at least one active developer.
I'm not exactly sure what the time frame should be to be considered for an active project, I've considered anything from one month (might be too short) to one year (probably way too long) to be considered inactive.