AraVox aims to help in writing dialogue trees for your game. It makes use of a custom scripting "language" with a syntax heavily inspired by {{mustache}} templates, specifically like handlebars.js. It lets you make use of functions and data in your script and have the AraVoxCursor node send signals to tell your UI what to do next (show a line, call a function, make a choice).

It also comes with its own editor with syntax highlighting. :)

There's also an extensive wiki listing all its features: https://github.com/aravikusu/AraVox/wiki