You can read about its early days in this document by Dan Ingalls and collaborators: <a href="http://www.vpri.org/pdf/tr1997001_backto.pdf" rel="nofollow">http://www.vpri.org/pdf/tr1997001_backto.pdf</a><p>and here:<p><a href="https://dl.acm.org/doi/pdf/10.1145/3386335" rel="nofollow">https://dl.acm.org/doi/pdf/10.1145/3386335</a>