Available only for backends

EFileCache — Simple file-based hash table for strings
Berkeley DB utilities — Utilities for Berkeley DB databases
ESoupAuthBearer — OAuth 2.0 support for libsoup
SQLite vfs
EUserPrompter — Manages user prompts over DBus
EUserPrompterServer — Server-side user prompter
EUserPrompterServerExtension — Extension for a server-side user prompter