Professional activities

I am a computer programmer. I've been doing contract work for the past 15 years. My specific areas of expertise include TCP/IP networking and BSD and Linux kernels. I am available for custom engineering work.  Please contact me at or (408) 270-6175.

Sample work committed into the FreeBSD and DragonFlyBSD kernel include
I also teach professionally.  My previous classes include
A resume is available on request.

Talks given

BSDCon 2003 San Mateo (pictures, more pictures)
AsiaBSDCon 2004
Tokyo 2004
NYCBSDCon 2005


Hsu, "Reasoning About SMP in FreeBSD", Proceedings of the BSDCon 2003 Conference, Usenix, 2003.

Hsu, "The DragonFlyBSD Operating System", Proceedings of the 2004 AsiaBSDCon, Usenix, 2004.

Named contributor to

[RFC3649] "HighSpeed TCP for Large Congestion Windows", 2003.

[RFC3782] "The NewReno Modification to TCP's Fast Recovery Algorithm", 2004.


I have two passions in life: wushu and programming. I like all forms of programming, but mostly I program on the BSD kernel.  I've been part of the FreeBSD Project since 1994 and was one of the first 10 FreeBSD committers, which grants write access to the master FreeBSD source repository.  Since that time, I have been offered an OpenBSD commit bit, worked on NetBSD professionally, and now spend most of my time working on the DragonFlyBSD fork of FreeBSD. Some sample work I've done to the FreeBSD kernel can be found here and to the DragonFlyBSD kernel here.

Recent Trips

I travel a lot, both to go to conferences to give talksIn my spare time, I enjoy traveling and skiing.

Hong Kong