[Home](../../) › [Metalama](../../metalama) › [Use Cases](../applications.md) › Classic Applications

# Classic Applications

> Metalama aids in implementing features for mobile, desktop, or web apps using design patterns, UI code patterns, and defensive programming.

Canonical: https://postsharp.net/metalama/applications/classics.html

Whether you're building a mobile, desktop, or web app, Metalama can help implement a broad set of features.

| Category | Patterns |
|----------|----------|
| [Classic Design Patterns](https://postsharp.net/metalama/applications/design-patterns) | Singleton, Memento, Factory, Builder, Decorator, Proxy |
| [UI Code Patterns](https://postsharp.net/metalama/applications/ui) <i class="supported"></i> | Change Tracking, INotifyPropertyChanged, Memoization, Undo-Redo, Command |
| [Defensive Programming](https://postsharp.net/metalama/applications/contracts) <i class="supported"></i> | Code contracts: pre-conditions, post-conditions, invariants, data annotations. |
| [Classic Object Services](https://postsharp.net/metalama/applications/object-services) | Deep Cloning, ToString, Comparison |

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