Optar

Optar (Optical Archiver) is a system for encoding data in a paper-printed code, like a large 2-D bar code, for archival purposes. 200 kilobytes of data can fit on one A4 page. The software for encoding and decoding it is open-source.

Links

 * Project page
 * Code
 * Optar download for Linux
 * Article on it in Wikipedia user space (not an official Wikipedia article)
 * Store data on paper with Twibright Optar
 * Scanned Optar code
 * Optar review