Quickly creating or editing objects. The main target would be editor extensions, image a snippet that expands to an object on tab for instance

Nickel looks like something akin to Nix (JSON with functions), whereas August’s goal is to allow you to quickly write a snippet that expands to your target document (e.g. via an editor extension) like Emmet. You can think of August like a snippet or shortcut to typing (or editing) a document rather than its own configuration language

I wouldn’t consider Melody a new flavour of regex as it compiles to ECMAScript regular expressions.

I’d consider being more verbose than regular expressions as a great thing for what this project aims to do, regular expressions are very write optimized which is the wrong (IMO) tradeoff to make in a shared codebase (or even your personal code that’s more than a few days old) where code is read much more often.