I'm Michael Driscoll. I used to work on tech startups. Now I ride bikes.


Almost everything I've done professionally is behind the wall of private intellectual property. It's an odd thing to spend decades doing work that you're proud of, but having nothing to show for it.

One of the few exceptions is a series of documents that I've written breaking down cryptographic and network protocols byte-by-byte. I'm always hearing from teachers, students, and fellow software developers who use these to learn, to fix, and to understand. I'm very proud of that.

About the name


When I was fourteen I needed a username to use a local BBS (back then we called usernames "handles" and thought it was very cool to have one). I took mine from a book I was reading, and the domain name "ulfheim" was based on it.

In the decades since then some awful people have attached their ideas to words that sound germanic, and unfortunately if you search for "ulfheim" you might find some of that. You can't truly reclaim something after it's been tainted, so I'm moving my hostnames to the new domain name xargs.org. All my ulfheim sites are mirrored to that new name.

   - Michael