These icons are based on the 88 by 31 pel licence buttons found on licensebuttons.net. Instead of low-resolution PNGs, they are fully vectorised SVGs, which are both lighter and, of course, scalable, rendering perfectly on today's high resolution displays.
The original Adobe Illustrator file is fukken saved in this repo as original.ai, with compatibility for Illustrator CS2 or later. All of the SVG files have already been optimised with the SVGOMG web utility.
I, Alexander Nicholi, the creator of these images, hereby release them all into the public domain. To the extent that is not legally possible, I hereby grant permission to everyone to use them without restriction, to the greatest extent permissible by law.