Updated README.MD

Author: ionut.stan

README.MD

@@ -2,9 +2,13 @@
 
 [![Build Status](https://travis-ci.org/oxygens/jsonrpc-bidirectional.svg?branch=master)](https://travis-ci.org/oxygens/jsonrpc-bidirectional)
 
-A main goal of this project is to have the JSONRPC server and client support __bidirectional JSON-RPC requests over a single WebSocket connection.__
+A main goal of this project is to have the JSON-RPC server and client support __bidirectional JSON-RPC requests over a single WebSocket connection.__
 
-Both the server and client support two __transports, HTTP and WebSocket__ ([websockets/ws](https://github.com/websockets/ws) compatible API), and allow more through plugin extensibility. 
+This library is tested in __browsers__ (at least Internet Explorer 10) and in __Node.js__ (at least 7.8, or 7.x with the --harmony flag.).
+
+Both the server and client support two __transports, HTTP and WebSocket__, and allow more through plugin extensibility. 
+
+For WebSocket client support it expects W3C compatible WebSocket class instances (browser `WebSocket` and Node.js [websockets/ws](https://github.com/websockets/ws) `WebSocket`). On the Node.js side it is tested to work with [websockets/ws](https://github.com/websockets/ws). `WebSocketServer` implementations are supported only if 100% API compatible with `websockets/ws`, or made compatible through an adapter.
 
 Plugins are allowed to replace the JSON-RPC protocol altogether, extend the protocol or wrap it.