Fudge was written by Steffan O'Sullivan ("With extensive help from the rec.games.design community"), and is available for free on the internet in a variety of places, most noticeably [FudgeRPG.com], home of Grey Ghost Press, who publishes a printed version of the game ("Fudge Expanded Edition", which also includes a basic fantasy setting), along with other support material for the game.
"Traits" in Fudge (That is, Attributes, Skills, Gifts, and Faults) are rated on a word based scale, from Terrible (-3), Poor, Mediocre, Fair, Good, Great, to Superb (+3). Fudge uses customized six-sided dice with two plus signs, two minus signs, and two blank sides. A number of these dice are rolled together - usually 4, or "4dF" in Fudge notation - to produce a result from -4 through +4, which is then applied the appropriate Trait, with the goal of matching or surpassing the Difficulty Level of the test. There are also several alternate dice systems that use regular six-sided dice.
Many Fudge resources, from alternate/expanded rules to campaign information to worldbooks are available online - the Grey Ghost Games site links to many of them.