I've started open sourcing more things lately, mostly in the realm of things that solve a problem I have that might solve someone else's problem. Sometimes I build tech for tech's sake that improves my software or apps, but it isn't a product in itself. Frameworks, libraries, templates, and tools all tend to fall into this category I think and github is a great example is open sourcing these things.

You shouldn't open source your product itself unless you want to be a service company. I personally don't care to become a service company, so I keep the "product" and the data behind it closed, but the frameworks, tools, etc. can and should when possible be open source.