The jQuery offline plugin provides an easy mechanism for retrieving JSON data from a remote server, and then caching it. Subsequent requests for the same URL will retrieve the data from the cache, rather than the remote server.

If the user is online, the plugin will transparently request new content from the remote server, firing the callback again if the content has changed. If the user is offline, the plugin will request the data from the remote server for the most recent request when the user comes back online.

jQuery Offline uses the HTML5 localStorage API for persistence. You can use the same API for browsers that do not support localStorage, jQuery Offline will simply fall back to making a request to the server each time. As a result jQuery.retrieveJSON is a portable way to make a request for JSON that should be cached if possible.

The DBacesslayer aka DBSlayer aka Släyer (as we like to call it when we're feeling ironically heavy metal) is a lightweight database abstraction layer suitable for high-load websites where you need the scalable advantages of connection pooling. Written in C for speed, DBSlayer talks to clients via JSON over HTTP, meaning it's simple to monitor and can swiftly interoperate with any web framework you choose.

Orderly is a textual format for describing JSON. Orderly can be compiled into JSONSchema. It is designed to be easy to read and write.

"Widget" to me means a user-interface element, like a button or something more complicated like a popup date picker, but in jQuery UI terms it means a class, members of which are associated with HTML elements; things like Draggable and Sortable. In fact, not everything that I would have called a widget uses $.widget; the UI datepicker does not.

This JSON parser does not attempt to validate the JSON, so may return a result given a syntactically invalid input, but does not use eval so is deterministic and is guaranteed not to modify any object other than its return value.

JSON.hpack is a lossless, cross language, performances focused, data set compressor. It is able to reduce up to 70% number of characters used to represent a generic homogeneous collection.

ZenQueue is a lean, network-available message queue, complete with server and client libraries, written in Python. It's been designed for simplicity, speed and portability.

JSON Diff is a simple way to visualize and compare JSON.

The Persevere project is an open source set of tools for persistence and distributed computing using intuitive standards-based JSON interfaces of HTTP REST, JSON-RPC, JSONPath, and HTTP Channels. The core of the Persevere project is the Persevere Server. The Persevere server includes a Persevere JavaScript client, but the standards-based interface is intended to be used with any framework or client.

oEmbed is a format for allowing an embedded representation of a URL on third party sites. The simple API allows a website to display embedded content (such as photos or videos) when a user posts a link to that resource, without having to parse the resource directly.