Troopers RedHack! You can easily see the B/X elements of this one, and author Pertros Moros designed the game to allow you to use modules and adventures from your gaming library. Petros has used Mutant Crawl Classics adventures along with OSE adventures and other systems, just tweaking some things to fit into the Troopers setting.
Troopers RedHack, is a classless system, allowing players to create the kind of character (Trooper) that they want to play. Wanna be a Combat Medic skilled in Guerilla Fighting or even a Psionic Trooper? easy peasy! The game is humancentric, although you can be an android and working up an alien pc looks pretty easy if you wanted to houserule some into the game. There is a default setting loosely baked into the game, but you can easily tweak/adjust or do your own thing, which I love. The print book is even digest sized which is awesome!
Troopers RedHack has a nice Appendix N, and while I had read many of the books listed many I have not, so I've been picking those up and reading them to get me in the Military Sci Fi mindset.
I also recently picked up the Aliens Colonial Marines Technical Manual! This should be a nice resource for my campaign. Not that I am planning to go full blown ALIENS, but the Colonial Marines gear, general info, etc. should be a cool resource to help me fill in a few details to the Troopers Campaign.
Well, that's all for now, I hope to post more about this game soon. Work has kept me pretty busy of late, hope you can get some gaming time in, enjoy time with friends and family!
-Good Gaming B.B.