QuickChannel is a developer library for sending messages between EAs/scripts running in different instances of MT4 on the same computer (or within a single copy of MT4). Typical uses include trade duplication between different MT4 accounts, and price comparison in order to detect arbitrage opportunities.
QuickChannel can also be used to communicate between MT4 and other applications. You can use it in any programming environment which allows DLL calls. For example, you can use QuickChannel in MT5, in cTrader, or in VBA code in Microsoft Excel. All these environments can communicate with each other. For example, you can use QuickChannel to send messages between MT4 and Excel, or between MT5 and cTrader.
QuickChannel can deliver messages in less than 1 millisecond, without the EA/script having to run in an infinite loop or use large amounts of processor power.
QuickChannel is used as the basis of the Personal Trade Copier.