The library behind the book Machine Learning and Big Data with kdb+/q by Jan Novotny, Paul Bilokon, Aris Galiotos, and Frederic Deleze is quantQ. It contains many scientific, quantitative, and computational functions implemented in pure q, and was designed to be highly readable and usable by kdb+/q programmers at all levels. This library is in public domain: https://github.com/hanssmail/quantQ