Free, built on open source and runs everywhere.

Among its features are:

• Start or plug in your running applications and debug with breakpoints, call stacks, and an interactive console;
• Provides smart completions based on variable types, function definitions, and imported modules;
• Debug the code right from the editor;
• Built-in Git commands;
• Extensions to add new languages, themes, debuggers and to connect to additional services.

VSCode Official Page