Noah Colony
Unbeknownst to the inhabitants of the Solar System, Noah's Ark, commanded by Richard Cromwell, made it through the wormhole, damaged but intact. When the Mars wormhole collapsed behind them, the colonists proceeded with their original mission: find a suitable planet and establish a colony. As prompted by earlier surveys by probes, an Earth-class planet existed in the system, which they promptly claimed as their own, dubbing the system and the colony planet "Noah." Some time after the arrival of Noah's Ark, the Noah Colony made contact with the Vardrag Confederacy, a highly advanced but peaceful alien race who offered the new arrivals a deal: the Vardrags would give the humans advanced technology and the IP Drives if, in exchange, the humans helped the Vardrags fight the battle against their warlike, reptilian enemies, the Gorg Empire.
 Vardrag Confederacy
The Vardrags are an unusual and extremely advanced alien race who had forged a large empire by the time they encountered the Noah colonists. The Vardrag homeworld has become a planet-sized city with enormous platforms in orbit. The Vardrags' main problem have been the constant skirmishes with the Gorg Empire. While Vardrag advanced weapons and defenses managed to keep the enemy at bay and despite their initially hideous biology, the Vardrags are pacifists - they severely disliked war. Discovering that the Noah Colony humans could be just as aggressive as the Gorgs, they gave the colonists advanced technology in exchange for their services as mercenaries. Most of their technology, however, was kept secret even from the Noah colonists; for example, technology that can force ships out of Interplanetary Drive mode, reactionless drives (labelled "gravity drives" in the game), extraordinarily resilient shields, and the massively powerful Cataclysm missiles. Vardrags prefer to travel in massive Cityships, larger and more powerful than either Noah or Gorg battleships. Leaving most of the fighting to their Noah Colony mercenaries and Raptor allies, they nevertheless maintain a defense force protecting their major systems from all kinds of threats.
Ghosts are a secretive and enigmatic race, inhabiting the system called Mist. They do, however, on occasion work as spies and scouts for the Vardrag Confederacy and the Noah Colony. All their communication is done either through text messages or a carefully-chosen representative, who is granted the honor of seeing the Ghosts' true form. It is suspected that the Ghosts have powerful psychic abilities that allow them to enhance their technology beyond what other races might achieve. Ghost ships are particularly weak as they are designed for stealth, not combat. The Ghosts' main strength lies in their Cloaking Device's ability to make their ships invisible to most sensors (except for close-range scans), hence their name. Their weapons are designed for precision strikes to allow a Ghost ship to disable an enemy ship and retreat before the enemy realizes the attacker.
 Mechanoids (Also known as "The Entity")
Little concrete information is available on the Mechanoids, except that they attempt to subjugate and/or destroy everything they encounter. According to the Vardrags, the recent Wormhole Cataclysm (realigning of the wormhole network) and the collapse of several stars are the works of the Mechanoids. There is a theory that they are rogue AIs created by the long-dead Creators, and are trying to remake the universe to fit their needs, even if it means they have to eliminate all who stood on their way.
The Mechanoid nanomachines themselves are not alive, but instead controlled by a vast and powerful artificial consciousness known as "The Entity". The mechanoid nanomachines can change their physical shape at will. Usually, they take on the form of a complex geometric shape about 1/8 the size of Angelwing and can fire a powerful energy blast that can destroy many ships in only a few shots. There have also been reports of massive Mechanoid spheres, ranging from the size of a Vardrag Cityship to half the diameter of Earth's Moon. They are capable of subjugating almost any machine -- even the ships of other races -- to their own ends, and can also take control of living beings if they have cybernetic implants.
The only thing known about the beings called the Creators, sometimes called Planners, is that they have monitored and, perhaps, directed humanity's development for centuries up until the 17th Century, when the last Creator died, leaving behind the secret base behind Pluto, the Angelwing, and a dormant AI who would later become known as Angel. It is hinted that the Mechanoids were also originally made by the Creators, but they betrayed and attacked their masters.
This bio-organic species acts much like its Terran namesake, consuming energy and bio-matter from any nearby sources, whether from ships, Mechanoids, or entire planetary eco-systems. Completely uncommunicative, they seem to exist only to feed, regardless of the consequences. While encountered only in two missions throughout the game, they are nonetheless deadly foes. The Locusts, being entirely organic, do not have starships, but instead are organized much like Earth's social insects, with three castes: Worker, Warrior, and Queen.
Text taken from Wikipedia