Public Collaboration. One of the major benefits of open source software is the public collaboration behind each project. Most open source projects are created by tens of thousands of programmers all collaborating to create, and improve upon, a flawless website framework.
Many software development companies use a proprietary, or home built, system as the framework for the websites they create. Open source software, such as WordPress and Drupal, were developed by thousands of talented developers. What would you rather own, a software package created by a handful of developers, or a software package created by thousands of developers?
Open source software promotes software reliability and quality by supporting independent peer review and rapid evolution of source code. A proprietary solution can not compare to that of open source.
Not bound to a single development company. With thousands of developers already 100% knowledgeable with your software framework, any open source friendly company can work on your website. Don’t be bound to a single development company because you are stuck using their proprietary software.
Auditability. Closed-source software forces its users to trust the vendor when claims are made for qualities such as security, freedom from vulnerabilities, adherence to standards and flexibility in the face of future changes. If the source code is not publicly available those claims remain simply claims. By publishing the source code, authors make it possible for users of the software to have confidence that there is a basis for those claims.