SeaweedFS
SeaweedFS is a fast, simple, and highly scalable distributed file system for storing and serving billions of files. Starting as an object store with O(1) disk seek performance, it has grown into a full-featured storage platform supporting S3 API, WebDAV, FUSE mount, HDFS, and Hadoop integration. The architecture separates concerns into a master server for volume management, a volume server for blob storage, a filer for directory/file abstraction, an S3 gateway for S3 compatibility, and a WebDAV server for mounted drive access. Features include erasure coding, cloud tiering, cross-datacenter replication, AES-256-GCM encryption, automatic compaction, file TTL, and a built-in admin UI. Licensed under Apache 2.0 with 30k+ GitHub stars.