---
title: Object Runtime
framework: foundation
role: collectionGroup
role_heading: API Collection
path: foundation/object-runtime
---

# Object Runtime

Get low-level support for basic Objective-C features, Cocoa design patterns, and Swift integration.

## Topics

### Object Basics

- [NSObject](objectivec/nsobject-swift.class.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [NSKeyValueCoding](objectivec/nskeyvaluecoding.md)

### Copying

- [NSCopying](foundation/nscopying.md)
- [NSMutableCopying](foundation/nsmutablecopying.md)

### Value Wrappers and Transformations

- [NSNumber](foundation/nsnumber.md)
- [NSValue](foundation/nsvalue.md)
- [ValueTransformer](foundation/valuetransformer.md)

### Swift Support

- [ReferenceConvertible](foundation/referenceconvertible.md)
- [Classes Bridged to Swift Standard Library Value Types](foundation/classes-bridged-to-swift-standard-library-value-types.md)

### Remote Objects

- [NSProxy](foundation/nsproxy.md)

### Memory Management

- [Memory Management Functions](foundation/memory-management-functions.md)

### Objective-C Runtime

- [Objective-C Runtime Utilities](foundation/objective-c-runtime-utilities.md)

### Versions and API Availability

- [Foundation Framework Version Numbers](foundation/foundation-framework-version-numbers.md)

### Legacy

- [Distributed Objects Support](foundation/distributed-objects-support.md)
- [Objective-C Garbage Collection](foundation/objective-c-garbage-collection.md)

## See Also

### Low-Level Utilities

- [XPC](foundation/xpc.md)
- [Processes and Threads](foundation/processes-and-threads.md)
- [Streams, Sockets, and Ports](foundation/streams-sockets-and-ports.md)