A Python timeline -- http://diveintomark.weblogger.com/pythontimeline
Tabs vs spaces: 'I'm pretty sure everything that can be said about tabs has been said. In fact there's probably enough material for a book or two: "A Concise History of Tab Usage", or "Professional Tabulation and Indentation Strategies for Python Programmers", or maybe "Tab Usage for Complete Idiots".' (Ken Seehof, 2001-Dec-5, comp.lang.python posting).