jLser

jLser is an open-source serializer library for JavaScript environments, designed to encode and decode complex data structures for transmission and storage. The project aims for compact representation, high performance, and cross-environment compatibility with both Node.js and web browsers.

Core functionality covers standard JavaScript data types—numbers, strings, booleans, null, arrays, and objects—with support for advanced constructs such as Map, Set, Date, and circular references. The library offers a configurable back-end that can emit a compact binary format by default and also provide a JSON-like representation for interoperability. It includes streaming APIs for incremental encoding and decoding and supports custom type serializers through a plug-in system.

jLser originated as an open-source project created in the late 2010s by a group of JavaScript developers. It is released under the MIT license and has received contributions from community members, with updates focusing on performance optimization and API usability.

Typical use cases include data transfer between client and server, caching, and inter-process communication. While not as widespread as JSON or other established binary formats, it maintains a small but active niche community and is referenced in several tooling ecosystems as an option when compactness or streaming is important.

See also: JSON, MessagePack, BSON, Protocol Buffers.