[Over the next two weeks leading to the Informa's open source conference, I 'll be looking at five traits which characterise open source software and its impact in the mobile industry, ranging from community culture, to what open source means for mobile Linux, browsers and Java.]

Open source software is one of the most hyped, misunderstood, feared and high impact phenomena in the software industry today. The success of Linux, from a pet project to Microsoft s arch-rival operating system has fostered hype for the success of the open source model. The unconventional business models where open source is employed, offer plenty of opportunity for misconceptions. Open source has also given rise to fear of IP contamination due to the copyleft properties of the GPL license. At the same time, open source software has created tidal waves within many facets of the PC and mobile industries, from operating systems to browsers.

So what on earth is open source? A Google search produces more than 25 distinct definitions of open source, each one from a different perspective. In practice, there are three distinct contexts in which open source is used today:

- Software that comes with an OSI-certified license.
The Open Source Initiative (OSI) is a non-profit organisation tasked with maintaining and promoting the definition of open source. The OSI defines 10 criteria for open source software, including that open source software must be freely distributable, access to source code and redistribution of modifications. Hundreds of open source-like licenses exist, of which the OSI has approved nearly 60. The vast majority of open source projects have been licensed under the GPL, the LGPL, the Mozilla Public License (MPL), the BSD License, the Apache Software License, and the MIT License.

- A social movement for making source code freely available.
For many, open source represents a social movement among software development communities. This movement supports that software should be freely available to anyone interested in using it, modifying it or redistributing it. Community-based development and viral distribution are important characteristics of this movement. The very term open source was coined to avoid misunderstandings arising from the earlier term free software .

- Open source as a collaborative development methodology.
From a business perspective, open source is a collaborative software development methodology whereby a community of entities and individuals (commercial, non-profit or entirely voluntary) develop software through a transparent, distributed peer review process. Open source development can pool community efforts towards development of a software base that is of common interest to all participating parties, while allowing differentiation through derivatives built upon this software base. In this sense, open source as a business model is the polar opposite to commercial forums, which foster collaboration through exclusive or paid-for membership. Yet in some cases open source development may be equally or more effective at achieving the same goal. An example of a successful open-source based collaborative software development effort is the Eclipse non-profit foundation which is backed by over 150 industry players, including heayvyweights Google, HP, IBM, Intel, Motorola, Nokia and Wind River Systems.

Open source started in the early 90s as a social movement in favour of maintaining software freedom; the development of the Linux kernel as a free Unix alternative and the creation of the GPL license were the two defining milestones of that movement. Yet 15 years on, open source has evolved gradually and perhaps unexpectedly into one of of the most succesful methodologies for commercial, collaborative software development.

- Andreas

[Want to learn more about open source and its impact on the mobile industry? Register for the pre-workshop 'A Crash Course in Mobile Open Source: Economics, Licensing, Linux, Java and Beyond' (see here for workshop agenda) delivered by VisionMobile as part of Informa's Open Source In Mobile conference taking place in Madrid on 17-20 September. Next on this blog series: how open source turns corporate software development on its head]