Frore is a barren, rocky world in the Tamaran system. In the 2005 GDC presentation, the Willosaurs came to the planet and deposited a Splodey on the surface, causing it to explode due to the lack of atmosphere. Later, the UFO of the Willosaurs created a bubble Colony on the planet, and used the Genesis Device to make it habitable. What happened to the colony and the planet afterwards is unclear besides the fact that the bubble was removed (according to Will Wright).
Frore had no native life, but Willosaur colonists transplanted animals and plants from their home world of Tamaran.
Frore originally had very uninteresting geography, which was mostly barren plains and many craters that littered the planet. After the Willosaurs terraformed the planet, there were low mountains and flat grasslands, similar to the geography of neighboring Tamaran, the Homeworld of the Willosaurs. It is also presumed that the Willosaurs added water to this formerly dead world.
Originally, Frore was just a dead world. Close inspection of the GDC video shows Frore had a close orbit to the Tamaran system's gas giant, but not orbiting it. This likely implies that Frore that was a former moon of this gas giant that somehow broke loose of its gravitational pull. Will Wright called it "moon". Frore would stay uninhabited until the Willosaurs colonized it.
The Willosaurs, who were exploring their home system came upon Frore and decided to colonize it. At first they just built domed cities on the surface, but they eventually created volcanoes to pump atmosphere onto the planet. Finally the Willosaus used a Genesis Device to accelerate the terraforming and then populated Frore with Tamaranian life.