Why I am using Linux:
Why "open source":
"Open" does have a value to most users, but it's not the source directly that's important. It's the fact that you have it, even if you never read it. The concept is similar to multi-sourcing other components: it's the fact that there are alternatives that matters, not whether you actually buy each screw from a different vendor.
Open source is firstly a sort of guarantee; because you have it, and because all the other customers have it, the vendor has to play fair. The mechanism is rarely invoked, but - like a "vote of no confidence" in parliament - it's important to have it available. It reduces risk.
Mature open-source products tend to have lower error rates (bugs/KSLOC).
Open source considers you a valued colleague rather than a thief. This is difficult to quantify, of course, but would you accept any other goods where you're assumed to have stolen them unless you keep the receipt? (This also leads to real costs such as compliance tracking and duplicate purchases.)
Open source offers a better path to becoming expert. Relatively few will take this path, of course, but when you do need an expert, you're more likely to be able to find/hire one (or become one, if necessary).
Last Updated: 14.9.2009