Riak CS been dead for over a decade which makes me question the rest. Some of these also do not have the same behaviors when it comes to paths (MinIO is one of those IIRC).
Also, none of them implement full S3 API and features.
Also, none of them implement full S3 API and features.
Ceph certainly implements the full API spec, though it may lag behind some changes. It's mostly a question of engineering time available to the projects to keep up with changes.
Sure, but those are S3 APIs and features that provided by AWS. We not talking about S3 spec, we're talking about s3 product.
When customer wants to switch away from AWS S3, customer cares about AWS S3 feature coverage and not the spec.
Also, who is rewriting their application to change interaction with an object storage? People that directly use some S3 sdk all around the app should read a book on software engineering or at least a blog post.