In the annual library systems report by Marshall Breeding in the ALA magazine - https://americanlibrariesmagazine.org/2018/05/01/library-systems-report-2018/ - there is mention of an interesting open source project called FOLIO, which will be an LSP (library services platform) as opposed to an ILS (integrated library system).
The most depressing thing in the report was its comment on Destiny.
No wonder the product isn't being developed effectively or efficiently. It's not that important to Follett.