just a small remark about Zotero:

I found a nice workflow which is ok for me and which does not require any plugin. TeXmacs has an internal bibliography database in which you can import .bib files and which can be kept in sync with a given bib file (see the Jolly Writer). I have a collection in Zotero where I put the papers which I want to cite in TeXmacs (I have a lot of papers in Zotero and only a small fraction I usually need to cite). Using the Betterbibtex plugin in Zotero I can automatically export this collection to a bib file as soon as it is changed. Then in TeXmacs I can ask to resync the internal database, so now I have my useful references synced between TeXmacs and Zotero and I can use autocompletion in TeXmacs to find them (it works only with the internal database). Note that in this way the references are added as metadata to the document and you do not need to carry around an auxiliary bib file, so make it easier to share the file.

Probably one can automate a bit more the workflow (automatic sync as soon as the .bib file changes) but I think it is not really necessary for my needs. I prefer to keep my TeXmacs setup simple.

HTH,

Best

Max