Stino itself is an open source plugin written in Python, and you can contribute to the project on Github. After installing Sublime and Stino, you point the plugin at an Arduino install folder.

Sublime Text is a proprietary, cross-platform text editor designed for people who spend huge amounts of time shuffling code around. A programmer's editor, Sublime Text is a third option to the ...

In addition, the Sublime Text API has been updated to Python 3.8, while preserving backwards compatibility with packages built for Sublime Text 3.