Röntgen is a set of monochrome 14 × 14 px pixel-aligned icons. All icons are under the CC BY license. So, do whatever you want but please give the appropriate credit.
Röntgen was created for Map Machine project to represent different map features from the OpenStreetMap database. However, it can be easily used for any map project or even for not map-related projects. Also, some icons can be used as emoji symbols.
All icons tend to support a common design style, which is heavily inspired by Maki, Osmic, and Temaki.
Feel free to request new icons via issues on GitHub.
Röntgen icons may be drawn by hand in vector redactor and stored as optimized SVG files, but also the project has one more option for icons extraction.
It may be useful to have one SVG file for a set of SVG icons along with sketches and components that icons consist of.
In the Röntgen project these files located in data directory.