Hans Thomas Reiser is an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 computer programmer, entrepreneur

Entrepreneur

An entrepreneur is an owner or manager of a business enterprise who makes money through risk and initiative.The term was originally a loanword from French and was first defined by the Irish-French economist Richard Cantillon. Entrepreneur in English is a term applied to a person who is willing to...

, and convicted murder

Murder

Murder is the unlawful killing, with malice aforethought, of another human being, and generally this state of mind distinguishes murder from other forms of unlawful homicide...

er. He is the creator and primary developer of the ReiserFS

ReiserFS

ReiserFS is a general-purpose, journaled computer file system designed and implemented by a team at Namesys led by Hans Reiser. ReiserFS is currently supported on Linux . Introduced in version 2.4.1 of the Linux kernel, it was the first journaling file system to be included in the standard kernel...

 computer file system

File system

A file system is a means to organize data expected to be retained after a program terminates by providing procedures to store, retrieve and update data, as well as manage the available space on the device which contain it. A file system organizes data in an efficient manner and is tuned to the...

, which is contained within the Linux kernel

Linux kernel

The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....

, as well as its attempted successor, Reiser4

Reiser4

Reiser4 is a computer file system, successor to the ReiserFS file system, developed from scratch by Namesys and sponsored by DARPA as well as Linspire...

. In 2004 he founded Namesys

Namesys

Namesys was a California corporation responsible for the design and implementation of the ReiserFS and Reiser4 filesystems. It has been inactive since late 2007, and as of 2010, is listed with the State of California with a status of "Suspended". Owned by Hans Reiser, Namesys was based in Oakland,...

, 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.