Document Revision History

This table describes the changes to SDK Compatibility Guide.

Date	Notes
2010-11-15	Added an explanation of how to use the `NS_CLASS_AVAILABLE` macro in Using Weakly Linked Classes in iOS.
	Updated and improved the Configuring a Project for SDK-Based Development and Using SDK-Based Development chapters.
	Improved the Using Weakly Linked Methods, Functions, and Symbols section by adding information on checking the availability of external symbols.
2010-02-16	Corrected an example that shows how to use conditional compilation macros.
2009-09-09	Clarified build setting information.
2009-05-12	Changed the title from Cross-Development Programming Guide. Added information about iOS SDK-based development. Revised text significantly and removed obsolete information.
2006-11-07	Added details on cross-development and universal binaries.
	Added chapter “Determining the Version of a Framework”. Noted requirement to build with GCC 3.3 when targeting OS X versions prior to OS X v10.3.0. Corrected OS X version requirements for code compiled with GCC 4.0. Added links to further information on building universal binaries from the command line. Changed deployment target in example.
2006-05-23	Corrected a build-setting specification and added per-architecture-build-setting availability details.
	Corrected specification for `LDFLAGS` build setting in “Configuring a Makefile-Based Project”. Added availability details for the per-architecture build settings feature.
2006-03-08	Added a link to Technical Note TN2163, which describes how to develop a universal I/O Kit driver.
2006-02-07	Made minor corrections.
	Added information on building universal binary versions of kernel extensions.
	Clarified use of `LDFLAGS`.
2005-11-09	Added a section on using cross-development to create universal binaries. Added information on identifying deprecated API. Corrected errors.
	Added “Cross-Development and Universal Binaries” chapter. Added Finding Instances of Deprecated API Usage. Reorganized content to create separate sections for configuring cross-development settings in Xcode and in makefile-based projects. Corrected sample code listing in Conditionally Compiling for Different SDKs.
2005-08-11	Fixed a bug in code that checks for the existence of a symbol. Updated steps for setting a deployment target to reflect Xcode 2.1.
2005-06-04	Updated information about checking for undefined functions. Added information about how to support SDKs from command-line programs.
2003-09-16	Made a number of changes throughout this document to reflect the final status of cross-development support as it shipped in OS X version 10.3.
2003-08-21	First general release of document.