Device capable of allowing space-faring craft to travel beyond the speed of light in hyperspace. Various advanced races have successfully constructed versions of this technology. Races who have built (or modified) hyperdrives, ranked in order of maximum known velocity, are: Replicators, the Asgard, the Goa'uld, humans, and the Wraith.
The Tollan likely also possessed hyperdrive technology. When Anubis attacked their Stargate was destroyed, forcing them to attempt to escape their homeworld in ships. The Talthuns are also believed to possess the capabilities to generate a hyperdrive window, but it should be noted that it is unclear just what, if anything, was responsible for moving their ships beyond the speed of light.
Replicators have been known to accelerate a Goa'uld Ha'tak's hyperdrive to 800-times its maximum speed. The Wraith's hyperdrive is known to be the weakest, as the vessels must make periodic hyperspace "pit stops," either because the technology is unsophisticated or they must stop to feed. The former is regarded as the most likely explanation.
Exactly what powers most hyperdrives is unknown. Typical naquadah ore is not sufficient to power the technology. When the Langarans introduced Earth to naquadria Samantha Carter hypothesized that it could be the missing link to what powers Goa'uld hyperdrives, but this is unlikely to be the answer -- since the Goa'uld Anubis was not familiar with naquadria. Instead, it is possible Goa'uld hyperdrives are powered by heavy liquid naquadah.
Within the Serpent's Grasp - SG-1 gets their first taste of hyperlaunch and extreme deceleration.
Exodus - The hyperdrive of SG-1's ship is affected by the shockwave of a star going nova, massively accelerating their course through hyperspace and stranding them in a distant galaxy.
Enemies - The Replicators buffer energy to a Goa'uld Ha'tak hyperdrive, allowing the craft to accelerate 800 times beyond its maximum speed.
Meridian - The nation of Kelowna proposes an exchange of naquadria with Earth.
Prometheus - The battle cruiser Prometheus launches from Earth and successfully opens its hyperdrive window for a few moments.
Memento - A failed hyperdrive experiment leaves Prometheus stranded on the other side of the galaxy.
Avenger 2.0 - SG-1 captures an Al'kesh, likely the ship hyperdrive will be removed for Prometheus.
Grace - Now powered by an Al'kesh hyperdrive, Prometheus accelerates its journey home.
The Siege, Part 3 - The Ancient Egyptian Zero Point Module is disconnected from the Daedalus hyperdrive, significantly reducing her overall speed in hyperspace.
The Hive - Colonel Caldwell pushes the Daedalus hyperdrive engines to enter the Pegasus Galaxy a few days early.
Adrift - The team works furiously to get Atlantis's hyperdrive working again, only to lack sufficient power to open a hyperspace window.
Lifeline - McKay and Zelenka manage to finish an experimental Puddle Jumper equipped with hyperdrive technology, which McKay started when he was made extra-brilliant by Ancient tech. The team successfully makes one hyperspace trip with the ship.