Hans Thomas Reiser (born December 19, 1963) is an American computer programmer, entrepreneur, and convicted murderer. He is the creator of the ReiserFS computer file system, which is contained within the Linux kernel, as well as its attempted successor, Reiser4. In 2004, he founded Namesys, a corporation meant to coordinate the development of both file systems. In April 2008, Reiser was convicted of the first-degree murder of his wife, Nina Reiser, who disappeared in September 2006.