Many in the library history community may be familiar with Al Kagan’s Progressive Library Organizations: A Worldwide History (Jefferson, NC: McFarland, 2015). Kagan has just published an update article to this book in The Journal of Radical Librarianship that is available open access at: https://journal.radicallibrarianship.org/index.php/journal/article/view/126/107
The first update article (covering 2013-2017) appeared in volume 4, 2018.