It also provides meta data about images, templates, functions etc. in order to simplify/help with Factorio API, with mod compabiltiy and data consistency.
All images from https://github.com/malcolmriley/unused-renders repository made by Malcolm Riley (the mentioned repository contains higher resolution images and wiki)
Maintainer of this repository: ZwerOxotnik
All changes can be tracked by git and provided into changelog.txt file
If you'd like to know how these sprites were made, please take a look at the wiki! Inside you'll find a tutorialized guide explaining Malcolm Riley's methods.
The resources in this repository are available under the Creative Commons Attribution 4.0 International License, as per the License included.