In the simplest terms, open source refers to computer program code where the source code is free for anyone to view and to study. There are many examples of open source: Linux is an open source operating system, and the world’s most commonly used CMS, WordPress is also open source. In other words, anyone can examine, edit or even distribute the source code of WordPress and Linux.
The open source model has unique characteristics compared to commercial software. In the case of open source software, anyone can view or study the code – but furthermore open source also means that anyone can improve the code by trying to test it or by reporting on errors – and even submitting fixes to the code, often received with gladness by a welcoming community of open source users.
Of course, some developers and users disagree with the idea of open source code: in part saying that open source code is more vulnerable than closed, commercial code – because everyone can view and study open source code, the argument goes, it makes it easier for hackers to find vulnerabilities.
Another argument is that open source doesn’t provide guarantees and warranties – in contrast to a commercial vendor. In other words, there is nobody to hold to account if something goes wrong with open source code, whereas a commercial vendor will in theory be accountable.
But, as is often the case, open source code has benefits too – which may well erase any concerns about open source issues. Benefits include the fact that open source means a unique level of customisability – including the ability to extend the software without the involvement of the original authors. WordPress is a prime example: it is easy to argue that the fact that WordPress is open source (and extendable and customisable) has led to it becoming the most popular CMS in the world, and indeed the most dynamic platform for publishing content on the web.