YDN-DB

A unified client-side database library for IndexedDB, WebSQL, and localStorage, currently at stable version 1.3.0. It provides a consistent asynchronous API across storage backends, supports schema version migration, advanced queries (including SQL-like and full-text search via additional modules), and transaction workflow management. Key differentiators include support for legacy browsers (IE6+, Chrome 4+, etc.), on-the-fly schema generation, managed requests to avoid InvalidStateError, and high-performance index queries using AVL trees for localStorage. Actively maintained until 2016, now in maintenance mode.