Snapchat/Valdi: Valdi is a cross-platform UI framework that delivers native performance without sacrificing developer velocity.

Valdi is an open-source cross-platform UI framework from Snapchat that compiles TypeScript components directly to native iOS, Android, and macOS views without web views or JavaScript bridges. Battle-tested in Snap's production apps for 8 years, it features automatic view recycling, instant hot reload, full VSCode debugging, and flexible integration with existing native codebases. The framework includes a C++ layout engine, worker thread support, native animations, and type-safe bindings between TypeScript and platform-specific code.