Open Source Software (OSS) has attracted enormous media and research attention since the term was coined in February 1998. The concept itself is founded on the paradoxical premise that software source code-the 'crown jewels' for many proprietary software companies-should be provided freely to anyone who wishes to see it. Given this fundamental initial paradox, it is perhaps hardly surprising that the OSS concept is characterised by contradictions, paradoxes and tensions throughout. In this paper we focus specifically on the following issues in relation to OSS: the cathedral v. bazaar development approach; collectivism v. individualism, the bitter strife within the OSS community itself (OSS v. OSS), and between OSS and the Free Software Foundation (OSS v. FSF); whether OSS represents a paradigm shift in the software industry; whether the software is truly open-the Berkeley Conundrum, as we have termed it here; whether OSS truly is high quality software; and whether OSS is a 'one size fits all,' representing the future model for all software development.