I'm looking for a good licence for software available publicly, but is in pre-alpha development stage (i.e., use it at your own risk and don't use it in any commercial software etc.)
As it's pre-alpha, the best license would be simply one that read something like "Don't use this for anything, even though it's online".
While it's here, "license" and "don't use this" are at opposite ends of the spectrum. If you want people to not use it, all you have to do is not license it and rely on basic copyright. You can post source code on a web page, just as you can post an essay on a blog, and that is conventionally interpreted as granting permission to look. A license is needed to actively copy. The basic idea of a license is to state what actions you allow, so for instance if you allow people to download and read offline, and nothing else, they you would say that. If you want to allow people to compile (when applicable), say that. And so on. If the point is to disclaim liability for damage, you should read up on warranty disclaimers. The CC license scheme is popular because it allows you to fiddle with distinctions. The main obstacle is deciding what you mean by "Open Source", since the least restrictive license (CC0 or PD) is what you want to make it "most open", but that depends on what you mean by "open".
