Does this kind of project exist anywhere else?
There are plenty of websites that contain historical records. But they're limited by what the websites choose to upload. There are also websites that crowdsource the indexing of historical records. Particularly genealogical websites such as Ancestry and FamilySearch. But again, those websites choose what fields to index, and they are usually only focused on items useful to genealogy.
At my local library, there is a copy of the street directory of my city a hundred years ago. As public information, I'm perfectly allowed to copy, transcribe, and index it. But, there's nowhere on the internet to do this.
I could imagine uploading PDF copies of such documents to Commons, and in the same way as wikisource allows, bringing that file over, and using OCR to transcribe most of it. Except, instead of creating a book out of it, we'd create a database. Choosing fields to be transcribed, and entering in every record. Users could then run queries like "First appearance of Queen Street". Or for my fellow genealogists, checking every instance of an address you know your ancestor lived at, to see when they first appeared there.
I don't think anywhere else allows the users to choose what will be archived or indexed. And I believe this is important information that WMF would be well placed to take care of. Supertrinko (talk) 00:59, 5 July 2021 (UTC)