Mozilla has once again launched their Extend Firefox contest this year, which is an effort to encourage developers to craft plugins for the infamous browser. As the most heavily-modified browser around, the plethora of 3rd-party plugins has been one of the keystones in making Firefox so successful. Obviously them encouraging this development helps.
The contest will be overseen by several judges from the field, including people from Mozilla, Yahoo, StumbleUpon, Netvibes, del.ici.ous and Adaptive Path. The contest lasts until the very end of this year, and will reward those developers who can innovate better than the rest.
You can read more details regarding the contest, along with information about another endeavor, "Operation Firefox", in the comments section. Last year, the Reveal extension was the winner, next to the Web Developer and Firefox Showcase plugins.