Free GM Resource: Freelance Traveller
Freelance Traveller has been around for a while, almost 6 years now, and is on their 71st issue.
Not too shabby.....
There are a couple of great things about this PDF magazine that don't even get into the content. 1st is that it is available in both Letter and A4 formats. Seriously.....who does that? Awesome in my book. They also have a consolidated listing of articles that is updated on a monthly basis.
These two things take a little bit of extra work, but really kick up the production value in my book. If you play any type of space-based RPG, you should really check out Freelance Traveller.