Security
Open-source software is more secured as the code is accessible to everyone. Anyone can fix bugs as they are found, and users do not have to wait for the next release. The fact that is continuously analyzed by a large community produces secure and stable code.
Cost
Open-source software is free to use, distribute, and modify. It has lower costs, and in most cases this is only a fraction of the cost of their proprietary counterparts.
Freedom
When businesses turn to open source software, they free themselves from the severe vendor lock-in that can afflict users of proprietary packages.
Interoperability
Open source software is much better at adhering to open standards than proprietary software is.