That actually means that the software (scripts in other words) is free like a Snowy Owl and it is for anyone to use, whoever finds it usable.
But, that doesn't mean that one can copy-pasta the software, use it and brag about it, without referencing and/or mention this domain at all. That's gay and cringe. Don't do that.
That is, some trace towards this domain is required. That means, one should keep the top most comments or block comments found wihtin source code.
To be more precise, I as developer, actually hate that shit related to licencing, but on the other hand, it has its logic and purpose, gotta admit .. because, we are living in a completely fucked up and shitty world.
All in all, the licence text is kinda very clear and well written and explains everything. Here, take Your pick: