Openstack is completely opensource and freely availalble under the Apache License. Meaning, you’re free to spin up your own cloud using their software. Openstack’s storage solution (Swift) is pluggable to be s3 compatible.
Openstack’s pluggability is where its true power lies. Its sourcecode is written in Python and actively maintained. They have many performance and security enhancements, as well as plugins ready to be installed.
|Cross Region Replication|
|S3 Compatible API|
|Management interfaces||REST api|
|Maximum object filesize||5 GB|
|Minimum object filesize|
|Recommended max file count per bucket||unlimited, with note that it’s not recommended to store more than ~1M, depending on hardware setup for the SQLite index|
|Max filesize for a bucket||unlimited|
|Maximum amount of buckets||unlimited|
|Authentication / ACL|
|Peering & interconnect|
|Unsupported Paid Feature Supported Unknown|