FlyJSONP is a JavaScript library for making cross-domain GET and POST requests to services that support JSONP, and get a JSON response.

The library is easy-to-use, there is nothing complicated, very lightweight (1.13kb gzipped) and doesn't require any other JS frameworks.

It passes the POST requests through Yahoo's YQL and provides a complete control over the callback parameter name for GET requests.

There is an online playground provided for giving the library a try.

Using JavaScript, it is possible to load HTML, XML or JSON data with XMLHttpRequest.

However cross-domain JavaScript requests (reaching remote pages) are not possible due to browser security limitations except JSONP-formatted JSON data.

Simple PHP Proxy is a PHP script which aims to fill this gap by creating a layer between your JavaScript code and the remote domain to get data in HTML, XML or JSON formats.

Some features of Simple PHP Proxy:

• requested URLs can be white-listed & validated against a regex.
• optionally forward client cookies / SID to the remote server.
• optionally forward configurable User Agent to the remote server.
• requests can use either GET or POST request methods.
• remote data can be delivered as-is with all remote headers intact.
• remote data can be wrapped in a JSON/P structure that includes status codes & remote headers.
• if using JSON/P & remote data is valid JSON, it will be merged into the resulting data object.

There is also a demo which you can request any URL.