If you're just starting out here, you might want to start with the FAQ.

• Use "Magic commands"
• Share values between languages
• Import NuGet packages
• Run code from other notebooks and source files using #!import
• Get input from the user
• Formatter APIs for .NET
• Language-specific features
  • C#
    • The C# Script dialect
    • PocketView
  • F#
    • F# Interactive (FSI)
  • JavaScript
  • PowerShell
    • PowerShell profile support
    • PowerShell host support
    • AzShell support
• Work with HTML
  • PocketView
• Multi-language notebooks with Jupyter

• Architecture
• Install as Jupyter kernel

• Using the .NET Interactive command-line interface

• Commands and events
  • Message protocol (TODO)
• Magic commands
• Kernel APIs
  • Variable sharing

• Adding support for new Jupyter subkernels
• Building your own extension
  • Adding magic commands