Star Frontiers, TSR's science fiction roleplaying game, gets a new face-lift in Bill Logan's excellently well-done remastered PDFs!
On his webpage, you can find PDF downloads of Alpha Dawn (Star Frontier's "core" rules), Knight Hawks (the spaceship campaign supplement), and Zeb's Guide to Frontier Space (originally intended to be the first of many volumes but only 1 volume got released; the guide revises Star Frontiers with a tighter, albeit universal-table-based system a la Marvel's FASERIP). Also available are remastered PDFs of Parts 2 and 3 of the Volturnus trilogy of modules (Part 1 of the story-arc is included as a sample adventure in the Alpha Dawn core rules), as well as tons of gaming aids from character sheets to quick references to map to minis--practically everything you need to get started adventuring on a far-flung frontier.
I've a fond space in my heart reserved for Star Frontiers. The game was one of the first RPGs I've ever run, after I got the Alpha Dawn boxed set as a gift from my father in the summer of '90. While it wasn't the first RPG I owned (that honor belonged to TSR's Conan RPG), it was the first I fell in love with: poster maps and cardboard counters and all. My group actually took a break from our favorite fantasy fare (I think it was High Fantasy at the time, since we didn't have D&D rules yet), and for the succeeding months, we played only Star Frontiers: from their first job as explorers aboard the Serena Dawn, to their subsequent crash landing on the (not-so) desert planet, and until they've united the local alien races in a huge war against the insidious Sathar in Starspawn of Volturnus. By that time, most of the original characters have been replaced with new ones, as the old ones died in the hostile Volturnus environment.
It was a fun and quirky system, but fun nonetheless.
My group has always talked about going back to it again, but other RPGs--among them various flavors of D&D--and time had so far confounded us. Flipping through these newly-remastered files, I feel an urge to revisit the Frontier once more. Maybe we will, one of these days, if the stars are right.