Have anyone ever used Delphi with NoSQL databases like Mongo, CouchDB or others? Which one would you recommend?
There is a new full featured driver for MongoDB "mongo-delphi-driver" which can be found (with examples) here: https://github.com/gerald-lindsly/mongo-delphi-driver.
For Mongo, theres TMongoWire and pebongo (early stages). For couchDB, I believe one would interact mainly through HTTP/JSON For Cassandra, I believe the best bet would be to somehow incorporate a supported language inside your Delphi app and use that to interact with Cassandra, or else implement a web service in a supported language and make it accessible to your Delphi application.
Hope it helps.
Delphi has few native NoSQL database solutions right-out-of-the-box:
Not that I suggest them, but you have not listed your requirements.