- Single WPF WinExe project (`net48`, `UseWPF=true`) whose entry point is `App.xaml.cs`; it bootstraps Exceptionless telemetry before showing the main window.
- MVVM layout: `BaseViewModel` provides `INotifyPropertyChanged` plus two in-process `ICommand` implementations (`RelayCommand`, `RelayAsyncCommand`). Each screen has a XAML view + code-behind window paired with a ViewModel (`MainViewModel`, `OptionsViewModel`, `ShardsViewModel`).
- `MainViewModel` owns the application lifecycle: reads/writes `Launcher.json` via Newtonsoft.Json, manages `ClientPaths`/`DataPaths`/`Plugins` collections, resolves shard hostnames through `Utility.ResolveAddress`, and finally `Process.Start`s `ClassicUO.exe` with `-plugins`, `-ip`, `-port`, `-uopath`, `-encryption`, `-shard` arguments. On exit it persists state back to JSON.
- Shard configuration is split between built-in presets in the singleton `ShardManager` (double-checked-lock single instance) and user-defined entries persisted in `Launcher.json`; `ShardsWindow` / `ShardsViewModel` edit them.
- ClassicUO launch flags are driven by reflection over `ClassicOptions`: each property is annotated with `ClassicOptionAttribute` (argument name, default value, conditional include rules), which both `ReadClassicOptions` (load from JSON) and `BuildClassicOptions` (emit CLI args) consume.
- UI helpers live in `Behaviours/` (WPF Interactivity behaviours), `Controls/EditTextBlock` (custom control), and `ValueConverters/` (boolean/cell-width converters). Resources are localized via `.resx` files under `Properties/`.
- Dependency direction: Views → ViewModels → `ShardManager`/`Utility`/`ClassicOptions`; no cross-viewmodel references except when one window passes its ViewModel into another (e.g. `ShowOptionsWindow` constructs `OptionsViewModel` with shared `Plugins`/`ClassicOptions`).