Pmrpc (https://github.com/izuzak/pmrpc) is an HTML5 JavaScript library for message passing, remote procedure call and publish-subscribe cross-contex communication in the browser. The library provides a simple API for exposing and calling procedures between browser windows, iframes and web workers, even between different origins. Pmrpc also provides several advanced features: callbacks similar to AJAX calls, ACL-based access control, asynchronous procedure support and fault-tolerance via retries. In case this wasn't clear, pmrpc is not a library for browser-server communication, it is a library for communication within the browser.