Cornerstone is a shared .NET 10 framework for desktop and cross-platform apps: process bootstrap, Keystone (Bus, State, Engine), lifecycle, sync and storage, and an optional UI runtime. Markup is .cxaml, compiled at build time.
Process entry builds one stack. Domain work stays in Keystone. Presentation is optional.
Process entry (console / desktop / mobile / browser / service)
└─ AppBootstrap.Initialize(…) process DI, runtime info, platform
└─ App services
├─ Keystone — Bus : State : Engine
├─ Lifecycle — Initialize → Load → Start → Process → Stop → …
├─ Sync and storage
└─ Presentation (optional)
├─ ViewModels + ViewIntegration
└─ AppDispatcher (attached ViewModels)
State is the model. The engine's processors mutate that state. The bus carries the messages. Processors run off the UI thread. When a view is attached, ViewModels and AppDispatcher project that state onto the screen.
| Piece | Role |
|---|---|
| AppBootstrap | Process-wide dependency injection and infrastructure (once per process) |
| Keystone | Domain Bus, State, and Engine, and its lifecycle tree |
| LifecycleTracker | Hierarchical Initialize → Load → Start, and reverse teardown |
| Sync and storage | Entity sync between a client and a server, and a source-generated SQL table mapper. Entity Framework is a separate package. |
| CornerstoneApplication | Shell that wires bootstrap, the dispatcher, and Keystone start and stop |
| AppDispatcher | Optional UI projection loop (attached ViewModels only) |
Most UI stacks treat native controls as a foreign window glued on top of everything else. Buttons, menus, and popups cannot sit over a live WebView, map, or video. Workarounds are snapshots, pause-and-cover, or "don't overlap." You are expected to pick: native content, or a real UI.
Cornerstone does not make that trade. Native and Cornerstone controls live as peers — equal in every way. A WebView, a map, a video player, and a toolbar are just controls in the same tree. You can stack them, overlap them, and mix first-party and third-party native SDKs without giving one side of the UI away.
Details: Native layering.
Sample apps in Applications/ run on Desktop, Android, iOS, and in the browser. Projects in Integrations/ host a third-party SDK. An app takes an integration with a project reference and builds it from this tree. Each SDK keeps its own license.
| Project | What it shows |
|---|---|
| Cornerstone.Navigator | A browser around WebView: address bar, back and forward, and favorites. |
| Cornerstone.MediaPlayer | MediaPlayerControl and playback chrome on the same four hosts. |
| Cornerstone.Esri | ArcGIS Runtime MapView and SceneView. GIS types stay Esri's. |
| Cornerstone.Vlc | LibVLCSharp VideoView. Playback types stay LibVLCSharp's. |
| Cornerstone.Mapsui | Mapsui map control. |
dotnet new install Cornerstone.Templates
dotnet new cornerstone.app -n MyApp
| Template | What you get |
|---|---|
cornerstone.basic |
Desktop window with AppBootstrap |
cornerstone.app |
Desktop app with AppBootstrap and Keystone |
cornerstone.all |
The same Keystone host on Desktop, Android, Browser, and iOS |
A UI app references Cornerstone and Cornerstone.Presentation. The analyzer ships inside Cornerstone, so both references are required to compile .cxaml. Default theme and product controls are already in Presentation. Entity Framework, PowerShell, and automation ship as their own packages.
Templates: Cornerstone.Templates/README.md. Documentation: Cornerstone.Documentation/Readme.md.
The aim is a framework for developers by developers: fast, open, free, and reliable, and software that makes building applications enjoyable. A release may miss a goal. If you run into an issue, we would love to hear about it.
Cornerstone is MIT. See license.txt.
Cornerstone.Presentation includes source from the other projects. The upstream license and the other third-party notices are in Cornerstone.Presentation/NOTICE.md.