---
title: Introduction to 64-Bit Transition Guide For Cocoa
framework: cocoa
role: article
path: apple-archive/documentation/Cocoa/Conceptual/Cocoa64BitGuide/Introduction
---

# Introduction to 64-Bit Transition Guide For Cocoa

Explains how to port Cocoa projects to 64-bit addressing.

## Organization of This Document

This document has the following chapters:

- [Moving to 64-Bit Addressing](../MovingTo64Bit/MovingTo64Bit.html#//apple_ref/doc/uid/TP40004247-CH3-SW1) provides background information about the 64-bit initiative for OS X and offers general advice for developers thinking about moving their Cocoa projects to 64-bit addressing. - [64-Bit Changes To the Cocoa API](../64BitChangesCocoa/64BitChangesCocoa.html#//apple_ref/doc/uid/TP40004247-CH4-SW9) describes the changes to data types for integers, floating-point values, enumeration constants, and other types of values in the Cocoa API. - [Converting an Existing Application to 64-Bit](../ConvertingExistingApp/ConvertingExistingApp.html#//apple_ref/doc/uid/TP40004247-CH5-SW1) explains how to run the script for converting a Cocoa code base to 64-bit and describes modifications you may have to perform manually after the script is run. - [Optimizing Memory Performance](../OptimizingMemoryPerformance/OptimizingMemoryPerformance.html#//apple_ref/doc/uid/TP40004247-CH6-SW1) describes common memory usage patterns in 64-bit applications and how to profile your application to find them.

## See Also

As a prerequisite to this document, read *[64-Bit Transition Guide](../../../../Darwin/Conceptual/64bitPorting/intro/intro.html#//apple_ref/doc/uid/TP40001064)*, which describes in full detail the reasons for the 64-bit transition, the fundamental changes to OS X to support 64-bit addressing, and the general requirements and procedure for building 64-bit executables.

[Next](../MovingTo64Bit/MovingTo64Bit.html)

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