I'm a geek. I write a bunch of software. Much of it I write for my employer and, as such, is confidential. However, I've also written a bunch of open source stuff over the years.

Image compression

jbig2enc - an open source JBIG2 encoder for bi-level images. The only open source one I think. This powers the PDF downloads on Google Book Search.

Haskell

I have a bunch of libraries on Hackage. I don't really have time to maintain them these days, but the popular ones have been taken over by others. Here's a list of ones that I written or significantly contributed to:

• binary-strict - a strict version of binary
• HsOpenSSL - OpenSSL bindings
• control-timeout
• codec-libevent
• ctemplate
• network-dns
• network-minihttp
• lru

Web Browsers

I'm currently working on the Linux port of Chromium (aka Google Chrome)

Cryptography

• rwb0fuz ("robo-fuzz") is a signature scheme, designed for DNSSEC, where the signatures are half the size of RSA at the same strength, can be verified 4x as fast and are provably as secure as RSA.
• curve25519-donna Donna is a family of implementations of the curve25519 elliptic-curve Diffie-Hellman function. It's used in DJB's NaCl library.