Why Free and Open Source Software?
Let's keep some arguments in favor of free and open source software here.
Cost versus Freedom
The Four Freedoms
Ability to Study Software
If you are a developer, just think how many times have you found a solution to your problem on web sites like StackOverflow or Github? This is possible because sites like these (for code sharing) promote and use open source. It is of immense help to students and also teachers to be able to see how some design patterns for example are implemented in some very large software projects.
Ability to Run Software for Any Purpose
Ability to Modify Software
- Not just software — translations too (you don't have to be a coder to participate!)
- Also design and visual modifications (for people with impaired sight or just to make software more user friendly and/or beautiful)
- Accessibility - if you have an open source product which runs great but it isn't accessible to people with special needs, it is much easier to modify it to fit that purpose. With proprietary software you would have to ask the author to implement this.
Ability to Distribute Modified Software
With following the rules defined by the included license of all open source products, you have the right to share the software by any means possible. This includes giving it to your friends or using it at your work place.
Open source software tends to be more secure than proprietary software, because of the much wider audience which can audit it.
From a developer and user stand point it is very important that the software they are using or creating (be it open source or proprietary) plays nice with each other. This can be only be achieved with well defined means of exchanging data which is done through the creation and usage of open standards.
FOSS is everywhere
With majority of the internet powered by FOSS, thousands of people making their living by working on (or around) FOSS and billions of devices running Linux, the point of open source is proved beyond doubt. Wherever you go, chances are that there is open source software in your vicinity.
Business Reasons for FOSS
The philosophy of software freedom / free software is a big enough reason for many individuals to choose FOSS. Many believe that FOSS is important in its own right, and that the "four freedoms" mentioned here are reason enough to prefer FOSS.
However, businesses typically do not choose software for philosophical reasons - or at least not philosophical reasons alone. However, it turns out that FOSS has many practical advantages for businesses, developers, and operations folks. Indeed, one could argue that it was practical reasons that caused Richard Stallman to set out to promote software freedom in the first place. Had Stallman been able to print happily we might not have the GNU GPL today.