This is currently in-development vaporware.
TON (Tree Object Notation) is a modern data language featuring two dialects: One for programmatic generation of data, and a static subset for safe data interchange.
TON is designed to be a pleasant and compact replacement for both XML and JSON, combining the best qualities of each, while allowing advanced users to programmatically generate large data sets using the full language dialect. At its simplest, TON can be used as a static data format just like XML or JSON, while at its full potential, it can be used to maintain large and complex textual databases at a level of maintainability that such data formats simply cannot achieve.
The original motivation for the creation of TON was the maintenance of the sorts of large data sheets that video games often use to describe things like areas, items, quests, characters, skills, etc. The code dialect should be well-suited to any similar use case. On the other hand, the data dialect can is well-suited as a safe and more compact replacement for XML and JSON, e.g. in networked APIs.
TON is an open standard. This project provides both the specification and the reference implementation in C#.