From the website:
Do you recognize the name Raiz? Leonid Raiz is one of the two founders of Revit, Irwin Jungreis being the other. Leonid's son Gregory founded Raizlabs 1997. Leonid has been working, in his spare time, on Thumbnail Explorer since retiring from Autodesk about two and half years after selling Revit to Autodesk. He recently released it to a small beta group and is now pleased to release it to the general public as a Raizlabs product.