Bok's official 'About' is as follows: Its hard to give a definitive definition but... Almal en alles is bok. Bewaarderbok. Bib(lioteek) bok. Bokrak(boekrak). Asbok(blik). So I'm not even going to try to explain. I'll just say they are three CT freelance designers/illustrators namely Johann Witbrood Botha, Dean Bruinbrood Steyn and Francois Linde. And they make and find bok (interesting/good/general positive adjective) things to look at.
Follow their tumblr or visit their Facebook page.