I was wondering if there are any open source blockchain libs that I could use to build a project with?
I agree. With my knowledge of bitcoin now and blockchain - I should have phrased this question better.
What I am looking for is a pure blockchain implementation (lib) that can be used to implement anything I want on top of it, one implementation could be bitcoin. This "blockchain 2.0" would not have the same limitations as blockchain today (hardcoded values, flexible message size, enhanced scripting language, etc..).
Lots of startups, companies, etc... implement their own blockchain because the bitcoins'version has been designed for bitcoin - it has not been designed to deal with other business problems.
Now I hope you see what I mean. But now I understand that I have to either do a hardfork of "bitcoin" and strip out "blockchain" - or I can try to find this "blockchain 2.0" that - for example - bitcoin could fork and be based on.
Do not be too quick to mark down. If it would be obvious, I would not ask for it ;-)