See JetBrains MPS: https://www.jetbrains.com/mps/ https://www.jetbrains.com/mps/ The "Projectional Editor" might be the kind of thing you're talking about. The

See JetBrains MPS: https://www.jetbrains.com/mps/ https://www.jetbrains.com/mps/ The "Projectional Editor" might be the kind of thing you're talking about. The meta language is stored as syntax trees rather than text and can be rendered in different ways.