Dotter is a dotfile manager and templater written in Rust. It manages symbolic links and Handlebars-based templates for configuration files, supporting conditional deployment based on variables, packages, and host-specific configurations. The architecture is a single CLI binary with subcommands for deploy, undeploy, init, watch, and shell completion generation. It reads TOML configuration files (global.toml, local.toml) that define packages, files, and variables, then merges them with optional includes and patches. The deployment logic uses a trait-based Filesystem abstraction to support real operations and dry-run simulation, with platform-specific handling for Unix (sudo elevation) and Windows (symlink detection). The codebase demonstrates strong Rust practices: extensive use of traits for testability, mockall for unit testing, comprehensive error handling with anyhow, and a modular structure separating concerns (config, actions, filesystem, handlebars helpers, diff). It is actively maintained with recent commits, CI/CD pipelines, and a well-documented wiki.