Praxis™ was designed in 1976 by Gerard Unger for the German technology corporation Dr.-Ing Rudolf Hell. Praxis is the sans serif counterpart to Demos, another early digital type designed by Unger, who is an accomplished Dutch typographer and teacher. Praxis and Demos share important characteristics, such as open counters, a tall x-height, and blunt stroke terminations. Both faces have very little thick/thin variation, which facilitates smooth linear enlargement and reduction. And like Demos, Praxis is a flexible and legible typeface that works well in small point sizes and on low-quality paper (office documents, newsletters, newspapers, etc.). The word "Praxis" comes from Greek, and means "a practical application." In the late 1990s, Demos and Praxis, along with Univers 57, were selected as the official typefaces of the German Government. More info. In 1990, Linotype AG merged with Dr.-Ing Rudolf Hell GmbH, forming the Linotype-Hell AG (today Linotype GmbH). Since then, Linotype has been the official source of all fonts that were originally designed for the Hell Corporation. Linotype has also improved the typefaces using new technologies, including OpenType."

A bunch of OpenType features to blacking out of texts. The font does not contain glyphs. Only black blocks that replace your text with OpenType features. Watch demo: https://youtu.be/qUQgUV0PIT0