Mork (file format)
Mork is a computer file format used by several email clients and web browsers produced by Netscape, and later, Mozilla Foundation. It was developed by David McCusker with the aim of creating a minimal database replacement that would be reliable, flexible, and efficient, and use a file format close to plain text.
Usage
The Mork format was used in most Mozilla-based projects, including the Mozilla browser suite, SeaMonkey, Firefox, and Thunderbird. In Firefox, it was used for browsing history data and form history data. In Thunderbird, it is still used for many things, such as address book data (.mab files) and the mail folder summaries (.msf files).
Criticisms
Mork has many suboptimal properties. For example, despite the aim of efficiency, storing Unicode text takes three or six bytes per character.
The file format has been severely criticized by Jamie Zawinski, a former Netscape engineer. He has lambasted the ostensibly "textual" format on the grounds that it is "not human-readable", bemoaned the impossibility of writing a correct parser for the format, and referred to it as "...the single most braindamaged file format that I have ever seen in my nineteen year career".