Variable Fonts - A simple resource for finding and trying variable fonts

https://medium.com/variable-fonts/https-medium-com-tiro-introducing-opentype-variable-fonts-12ba6cd2369

Version 1.8 of the OpenType font format specification introduces an extensive new technology, affecting almost every area of the format. An OpenType variable font is one in which the equivalent of multiple individual fonts can be compactly packaged within a single font file. This is done by defining variations within the font, which constitute a single- or multi-axis design space within which many font instances can be interpolated. A variable font is a single font file that behaves like multiple fonts.