There is absolutely nothing in place that would prevent absolutely any app developer to build a world-class integration with Zotero. If you have trouble convincing on the userbase part - plenty of people on these forums will be happy to get you started on a Zotero plugin that gets you the desired behavior. This explains the MS Word, LibreOffice, and Google Docs integrations - Google, MS and the LO devs made extension points & docs available, and Zotero built the world-class integration on top of this.
If the app developer wants someone else to do the work, all this app developer has to do is give us extension points into the app, documentation on how to use them, and explain how it would benefit enough of the Zotero users that it would fit the Zotero mission to spend their resources on it. Zotero has ample extension points, and if you're willing to venture outside those, that's very possible, and then there's very little you can't achieve with a Zotero plugin to create any integration you want/need.
In principle, an app developer doesn't have to do anything special towards Zotero to get full integration. (But however much guidance you can give, even if it's not very much, could still yield impressive dividends.) So, writing adequate guidance is an investment that would pay huge dividends as more and more text editors achieve first-class Zotero integration without addition work from Zotero devs. With a sufficiently clear and thorough answer, they might even be able to do 100% of the work involved in achieving first-class integration. But my hope is that this post might become a resource to which interested projects can refer.
I know that this question might require a fairly comprehensive answer, which is more effort than the typical forum answer. If an app developer is interested in keeping the door open for first-class integration with Zotero, what do they need to know? How can they set themselves up to make that as easy as possible later? But it isn't too late for all other projects! It's a shame because it seems that a bit of foresight could've made sure that impasse was avoided, but oh well. Scrivener or Zotero would need to be rebuilt from scratch, which isn't going to happen. In the past, I recall seeing a discussion about how Scrivener is unlikely to get Zotero integration because it was built in a way that simply isn't compatible.
Still good, but not as fantastic as what I'm calling first-class integration.Įvery other text editor can work with Zotero via the RTF/ODF Scan plugin, which is wonderfully enabling because of the freedom of choice it allows, but still isn't on the same level as first or second-class integration. Some other text editors, like Zettlr, have a second-class type of integration. MS Word, LibreOffice, and Google Docs enjoy first-class integration with Zotero.