Simply Jonathan

Reverse Engineering the Notability File Format 

A turn-by-turn description of how Julia Evans reverse engineered the proprietary image format used by the iOS Notability app.

As she says:

People don’t usually invent totally custom file formats! Nothing in here was really complicated – it was just some existing standard formats (zip! apple plist! an array of floats!) combined together in a pretty simple way.

This is Simply Jonathan, a blog written by Jonathan Holst. It's mostly about technical topics (and mainly the Web at that), but an occasional post on clothing, sports, and general personal life topics can be found.

Jonathan Holst is a programmer, language enthusiast, sports fan, and appreciator of good design, living in Copenhagen, Denmark, Europe. He is also someone pretentious enough to call himself the 'author' of a blog. And talk about himself in the third person.