New Backgrounds:
Star Trek
Star Trek: The Original Series by Alan Brain: For everyone who remembers the days of Kirk, Spock, and Bones.
Full Trek by Scott Field: Star Trek conversions rules in HTML Format or Plain Text Format. Here is are some updated stats for his ships.
FASA Star Trek --> Full Thrust: Rules for FASA late Star Trek game.
Star Wars
Star Wars/FT 2.5 by Phillip Pournelle: Rebel and Imperial ships created using the construction rules found in the FT Fleet Book.
Ships and Rules For Star Wars, author unknown: A long time ago....
More Star Wars Ships by Paul Neher: More ships from the fleets of the Rebel Alliance and the Empire.
Star Wars Crossover by Phil Pournelle: Rules for combining FT and Star Wars Miniature Battles.
Babylon 5 (Warning: These rules contain major spoilers for the show!)
B5/FTII Conversion by David Scott: Rules in MS Works 3.0 format. There is a seperate file for David's ship designs all in a .ZIP file.
Mark "Indy" Kochte's Babylon 5 Rules: I highly recommend these rules for B5 fans.
Tom McCarthy's Babylon 5 Rules by Tom McCarthy: An updated version that now includes Shadow Tech.
Marshall Grover's Babylon 5 Rules by Marshall Grover: This .ZIP file contains a new version of Marshall's rules and a MS Excel construction worksheet.
Battlestar Galactica
Full Galactica Thrust Rules by William Hostman: Eat your heart our Starbuck and Apollo!
Ships and Rules for Battlestar Galactica by Phillip Atcliffe: "Fleeing the Cylon tyranny, the last Battlestar, Galactica, leads a rag-tag, fugitive fleet on a lonely quest: A shining planet known as Earth."
Anime
Star Blazers/Yamato Rules by R Meaden: Ships and rules to play in the classic TV series.
Literature
Honor Harrington:
Honor Harrington Rules by Darryl Adams: Rule for playing FT in the popular David Weber universe. (Just don't get Nimitz upset.)
Jerry Han's Honor Harrington Rules: More rules featuring everyone's favorite female starship captain (and I'm not talking about Cpt. Katherine "Laryngitis" Janeway.)
Other Games:
Space Fleet/Battlefleet Gothic:
Space Fleet -- Traditional Conversions to FTII by Aaron Teske: Rules to play Space Fleet battles in FT (no rolling dice in to a stupid box). Now he has rules for FT 2.5.
Traveller:
Traveller Rules For Full Thrust by Steve Parsonage: More rules to play FT in the universe of Marc Millers Traveller RPG.
Starfleet Wars:
Starfleet Wars by the M Collective: Rules to play FT with the classic Superior Models miniatures.