MetaTrader (MT) is probably the most popular online trading platform. Currently, MetaTrader has two versions MT4 & MT5. MT4 is primarily focused on forex trading while MT5 also supports stock trading. They also support some commodity and crypto trading as well. MetaTrader platform allows the development of automated trading robots called expert advisers and also indicators and scripts developed with MQL, an object-oriented, proprietary programming language with syntax based on the C programming language.
TradeStation is one of the most popular trading platforms for stocks, options and futures trading. TradeStation delivers all the power, speed and flexibility active traders demand: dynamic market-scanning tools, fully customizable charting, fast and reliable trade execution, advanced order management and fully automated strategy trading. TradeStation needs EasyLanguage, a proprietary programming language used to create custom indicators and algorithmic trading robots.
cTrader is an advanced platform, designed especially for Forex trading. cTrader provides a fully customizable interface and many savable chart templates for all possible technical trading analysis strategies. Automate, allows traders to develop custom trading robots to automate trading. The Automate functionality is extensive, supports all types of Forex and CFD trading. cTrader requires cAlgo, a proprietary programing language that allows developing algorithmic trading systems and customized technical indicators.
TradingView is a web-based social network for traders and investors on forex, futures, and stock markets. It features integrated news, market analysis, and advanced charting capabilities accessible from any type of web browser. TradingView has its own lightweight scripting language called Pine Script. It allows users to create custom indicators and automated trading strategies. Pine is cloud-based and therefore different in nature to client-side programming languages.