When I use a Mac, can I use Zotero and ZoteroBib successfully? Do they need to both be used and can I easily transfer from ZobetoBib direct into my Zotero library?
With Zotero, you don't need ZoteroBib. Zotero is a database that stores and organizes your references (on your local computer, and can also sync online if you want), and also can create bibliographies. ZoteroBib is a quick tool that creates temporarily bibliographies from a list (and can sometimes store that list in your browser, but should not be relied upon as permanent storage). So you can use both, but you don't need to, and they are not directly integrated with each other. You could export your current list from ZoteroBib into Zotero, though, and then work from there. ZoteroBib is a very limited, simplified version of Zotero with less features. It works for some purposes, but for serious research, especially ongoing projects with the same references, having Zotero is very valuable.
Zotero works well on Macs,* and ZoteroBib works in your browser so it doesn't depend on one OS or another.
[*The only limitation on Macs is that if you're using integration with MS Word to insert citations and generate bibliographies, due to limitations of plugins in Mac Word from Microsoft, it can run very slowly in extremely long documents (e.g. hundreds of citations). But there are workarounds: https://forums.zotero.org/discussion/91573/zotero-word-connection-extremely-slow#latest]
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See: https://zbib.org/faq
Zotero works well on Macs,* and ZoteroBib works in your browser so it doesn't depend on one OS or another.
[*The only limitation on Macs is that if you're using integration with MS Word to insert citations and generate bibliographies, due to limitations of plugins in Mac Word from Microsoft, it can run very slowly in extremely long documents (e.g. hundreds of citations). But there are workarounds: https://forums.zotero.org/discussion/91573/zotero-word-connection-extremely-slow#latest]