Does anyone know anything about the “Terraformers” from the Starcraft universe?

The Terraformers were an ancient, highly advanced species that were responsible for the terraforming of the planet Xel’Naga. The only known event involving the Terraformers occurred over 6 million years ago, and the only remnants of them are the Xel’Naga.<br><br>Is this just a random event that occurred to explain how the Xel’Naga came to be, or is there anything else known about them? I’ve always wondered why the Xel’Naga would do what they do and act how they do, if they were a completely artificial entity.