This repository is a Go reimplementation of the TypeScript compiler, including a full type checker, emitter, parser, and language server (LSP). It provides a CLI tool `tsgo` for compilation, watch mode, and build mode, and a native-preview npm package that wraps the Go binary for Node.js integration. The architecture is a monolith with well-organized internal packages (e.g., `internal/compiler`, `internal/checker`, `internal/ast`, `internal/lsp`). The codebase demonstrates high craftsmanship with clean abstractions, generic utilities, and extensive test coverage using a custom fourslash testing framework. It is actively maintained but explicitly slated for permanent archiving in September 2026, as development will continue in the main TypeScript repository. The repo is a staging ground for the TypeScript 7.0 native port and is not yet feature-complete (language service is in progress).