MSL (Minecraft Server Launcher) is a Windows desktop application for managing Minecraft server instances. It allows users to create, configure, launch, and monitor Java and Bedrock Minecraft servers, including mod/plugin management, server core downloading, world backups, and crash analysis. The application also provides networking capabilities through FRP tunneling (supporting multiple providers like MSLFrp, OpenFrp, SakuraFrp, ChmlFrp, and custom frpc) and P2P/STUN connections for online play. It includes a download manager for concurrent file downloads, a system resource monitor, and a terminal emulator (ConPTY) for server console interaction. The architecture is a monolithic desktop application built with .NET Framework 4.7.2 using WPF and the HandyControl UI library. The UI is composed of pages loaded into a main window, with separate modules for server runner (dashboard, console, settings), FRP management, download manager, and settings. Configuration is stored in JSON files with atomic writes. The application integrates with several external APIs (MSL backend, CurseForge, Modrinth, BMCLAPI, and various FRP provider APIs) via a custom HTTP service. Key entry points include App.xaml.cs (application initialization), MainWindow.xaml.cs (navigation hub), and ServerRunner.xaml.cs (per-server window with child pages). Data flows involve HTTP requests to external APIs, local JSON config files, and process I/O for server and FRP binaries. The application uses a custom ConPTY terminal emulation library for server console I/O and a language system for internationalization. External dependencies include .NET Framework 4.7.2, HandyControl (submodule), Newtonsoft.Json, SharpZipLib, AvalonEdit, CurseForge .NET API client, Modrinth .NET client, QR code library, and ConPtyTermEmulatorLib. The application relies on external services: MSL API (mslmc.cn), CurseForge, Modrinth, BMCLAPI, and various FRP provider APIs.