MetaQuotes Language 5 (MQL5) is a high-level language designed for developing technical indicators, trading robots and utility applications, which automate financial trading. MQL5 has been developed by MetaQuotes Software Corp. for their trading platform. The language syntax is very close to C++ enabling programmers to develop applications in the object-oriented programming (OOP) style.
In addition to the MQL5 language, the trading platform package also includes the MetaEditor IDE with highly advanced code writing tools, such as templates, snippets, debugging, profiling and auto completion tools, as well as built-in MQL5 Storage enabling file versioning.
The language support is available on the MQL5.community website, which contains a huge free CodeBase and a plethora of articles. These articles cover all the aspects of the modern trading, including neural networks, statistics and analysis, high-frequency trading, arbitrage, testing and optimization of trading strategies, use of trading automation robots, and more.
Traders and MQL5 program developers can communicate on the forum, order and develop applications using the Freelance service, as well as buy and sell protected programs in the Market of automated trading applications.
The MQL5 language provides specialized trading functions and predefined event handlers to help programmers develop Expert Advisors (EAs), which automatically control trading processes following specific trading rules. In addition to EAs, MQL5 allows developing custom technical indicators, scripts and libraries.
This MQL5 language reference contains functions, operations, reserved words and other language constructions divided into categories. The reference also provides descriptions of Standard Library classes used for developing trading strategies, control panels, custom graphics and enabling file access.
Additionally, the CodeBase contains the ALGLIB numerical analysis library, which can be used for solving various mathematical problems.
MQL5 programs are divided into four specialized types based on the trading automation tasks that they implement: