my WIP is actually based off of a timeline I created myself using a simple word processor back in 2009. Honestly you don't really need any type of specific software to do this. In fact, since I know a little bit about web design, I created an interactive timeline for the WIP for a project, and then later around 2011, I filled out some encyclopedic pages about the break down of the religions, families, economy, and politics in the world. Not all of them, just the basics.
However, I learned the hard way that the story has to come first. I was sitting on this wonderful world for 6-7 years before I came up with a worthy story to tell about it.