MetaQuotes Language (MQL) is a programming language used exclusively with MetaTrader Software to create automated trading robots and financial market indicators. Programmers who write MQL scripts must have a strong grasp of object-oriented programming, MQL syntax, and the financial markets in which they plan to deploy MQL scripts. The goal of writing MQL scripts is to automate the process of analyzing financial markets, primarily foreign currency exchange markets (Forex), and trading financial instruments based on that analysis.

MQL is an object-oriented programming language with syntax based on the C programming language. As a result, programmers who already know C, or closely related languages such as Java or C++, will find MQL syntax familiar, and pick up the language quickly. While MQL can be written in a plain text editor, it must be compiled in MetaTrader. The client versions of MT4 and MT5 are free and both include an integrated development environment (IDE) known as MetaEditor. The simplest place to write MQL is within MetaEditor.
MQL4 and MQL5 are programming languages used to create trading robots and financial analysis tools to deploy on the MetaTrader 4 and 5 trading platforms.