Theodore Ts'o

Appearance move to sidebar hide
Theodore Yue Tak Ts'o
Born1968 (age 55–56)
Palo Alto, California
Other namesTed
Alma materMassachusetts Institute of Technology
Occupation(s)Computer scientist, free software developer
Known forInvolvement in FOSS, e2fsprogs
AwardsAward for the Advancement of Free Software

Theodore Yue Tak Ts'o (Chinese: 曹子德; born 1968) is an American software engineer mainly known for his contributions to the Linux kernel, in particular his contributions to file systems. He is the secondary developer and maintainer of e2fsprogs, the userspace utilities for the ext2, ext3, and ext4 filesystems, and is a maintainer for the ext4 file system.


Ts'o graduated from MIT with a degree in computer science in 1990, after which he worked in MIT's Information Systems (IS) department until 1999. During this time he was project leader of the Kerberos team.

In 1994, Ts'o created the /dev/random Linux device node and the corresponding kernel driver, which was Linux's (and Unix's) first kernel interface that provided high-quality cryptographic random numbers to user programs. /dev/random works without access to a hardware random number generator, allowing user programs to depend upon its existence. Separate daemons such as rngd take random numbers from such hardware and make them accessible via /dev/random. Since its creation, interface /dev/random is used in Linux, FreeBSD, macOS, and Solaris systems.

After MIT IS, Ts'o went to work for VA Linux Systems for two years. In late 2001 he joined IBM, where he worked on improvements in the Linux kernel's performance and scalability. After working on a real-time kernel at IBM, Ts'o joined the Linux Foundation in late 2007 for a two-year fellowship. He initially served as Chief Platform Strategist, before becoming Chief Technology Officer in 2008. Ts'o also served as Treasurer for USENIX until 2008, and has chaired the annual Linux Kernel Developers Summit.

In 2010 Ts'o moved to Google, saying he would be working on "kernel, file system, and storage stuff".

Ts'o is a Debian Developer, maintaining several packages, mostly filesystem-related ones, including e2fsprogs since March 2003. He was a member of the Security Area Directorate for the Internet Engineering Task Force, and was one of the chairs for the IPsec working group. He was one of the founding board members for the Free Standards Group.

In July 2023, Ts'o joined RESF's Board of Directors, which encompasses the Rocky Linux project.


Ts'o was awarded the Free Software Foundation's 2006 Award for the Advancement of Free Software.


  1. ^ "random.c" (source code). Archived from the original on 2012-07-14.
  2. ^ "Randomness shouldn't be left to chance", Linux certified (howto)
  3. ^ "How good is LavaRnd?: Detailed Description of Test Results and Conclusions". LavaRnd. 22 Sep 2004. Archived from the original on 2007-04-03. Retrieved 21 June 2011.
  4. ^ "Linux Kernel Developer Ted Ts'o Joins Linux Foundation as Chief Platform Strategist". The Linux Foundation. December 4, 2007. Retrieved 21 September 2018. The Linux Foundation (LF), the nonprofit organization dedicated to accelerating the growth of Linux, today announced that Linux kernel filesystem maintainer Ted Ts'o is joining the organization as a Fellow and chief platform strategist.
  5. ^ "Linux Foundation Appoints Ted Ts'o to Position of Chief Technology Officer". The Linux Foundation. December 18, 2008. Archived from the original on 2008-12-20. Retrieved 2008-12-21.
  6. ^ "Ted T'so moves to Google". The H Open. 14 January 2010. Retrieved 21 September 2018. Theodore 'Ted' T'so has moved to Google, leaving his position as Linux Foundation's Chief Technology Officer.
  7. ^ "Proud to be a Googler". Retrieved 14 January 2010. I'm going to be working on kernel, file system, and storage stuff. Ext4 will definitely be one of the first things I'll be working on,
    See: Michael Rubin (4 January 2010). "Re: benchmark results".
  8. ^ "RESF Names Theodore Ts'o to Board". 3 July 2023. Retrieved 3 July 2023.
  9. ^ "Ted Ts'o wins the 2006 Award for the Advancement of Free Software". Free Software Foundation. 26 May 2007. Retrieved 7 June 2021.

Further reading