ACORN (Atozed Compact Object Readable Notation) is a standardized open freely usable format for storing objects and other data types in a compact readable format.

ACORN was initially developed for IWML after JSON and XML were found to be not well suited.

Open Standard

The ACORN format will be fully documented and existing parsers and serializers to use ACORN will be open sourced.

In addition to filling a need in between JSON and XML, ACORN was designed to be easily parsed in any language using simple line based parsing rules.

Used For

ACORN is the base type for IWML, and raw ACORN files are also used for configuration and other files by IntraWeb.


While developing IWML we initially used XML and found it to be very chatty, while JSON was too shifty (all those ” will give a person carpel tunnel quickly) as well as too limited in many areas especially around mixed arrays. The workarounds needed to conform to JSON’s simplicity made the resulting data files more complex than desired.

Thus ACORN was born and designed to be simple without all the complex baggage of XML, yet more capable than the overly simplistic JSON.

Technical Data

Mime Type: text/acorn
File Extension: .nut