Wormhole — it's better EventEmitter for communication between tabs with supporting Master/Slave.

Immutable and structurally typed data

A persistent job or task queue backed by RethinkDB.

WebAssembly port of SQLite3 for Node.js with file system access

Persistent multiplayer map of pins and stories.

Immutable finite list objects with constant-time equality testing (===) and no memory leaks.

🍭🧁⛱️📦Cache all kinds of remote dependencies.

🌵 Finger tree data structure for JavaScript

saves video/audio volume

HTTP server with sessions, tokens, cookies

An Immutable vectors/lists/arrays library using the Relaxed Radix Balancing(RRB) technique

🌲 Persistent data structures for JavaScript

📅🪁 A persistent Redis job scheduler

A directly and easy way to keep mobx observable persistent.

DeriveODM is a reactive ODM - Object Document Mapper - framework, a "wrapper" around MongoDB, that removes all the hassle of data-persistence by handling it transparently in the background, in a DRY manner.

Persist Hook : Give me a key, I'll make your React Hook's state persistence.

svelte store with persistent storage (indexeddb, websql,localstorage)

Persist Model for redux-persist

Persistent ordered dictionaries via AA trees, with a Cursor API