Xcode is an integrated development environment (IDE) for macOS containing a suite of software development tools developed by Apple for developing software for macOS, iOS, iPadOS, watchOS, and tvOS. First released in 2003, the latest stable release is version 10.3 and is available via the Mac App Store free of charge for macOS Mojave users. Registered developers can download preview releases and prior versions of the suite through the Apple Developer website.
Xcode supports source code for the programming languages C, C++, Objective-C, Objective-C++, Java, AppleScript, Python, Ruby, ResEdit (Rez), and Swift, with a variety of programming models, including but not limited to Cocoa, Carbon, and Java. Third parties have added support for GNU Pascal, Free Pascal, Ada, C#, Perl, and D.
Xcode can build fat binary files containing code for multiple architectures with the Mach-O executable format. These are called universal binary files, which allow the software to run on both PowerPC and Intel-based (x86) platforms and that can include both 32-bit and 64-bit code for both architectures. Using the iOS SDK, Xcode can also be used to compile and debug applications for iOS that run on ARM architecture processors.
Xcode includes the GUI tool Instruments, which runs atop a dynamic tracing framework, DTrace, created by Sun Microsystems and released as part of OpenSolaris.
Xcode 1.0 was released in fall 2003. Xcode 1.0 was based on Project Builder but had an updated user interface (UI), ZeroLink, Fix & Continue, distributed build support, and Code Sense indexing.
The next significant release, Xcode 1.5, had better code completion and an improved debugger.
Xcode 2.0 was released with Mac OS X v10.4 “Tiger”. It included the Quartz Composer visual programming language, better Code Sense indexing for Java, and Ant support. It also included the Apple Reference Library tool, which allows searching and reading online documentation from Apple’s website and documentation installed on a local computer.
Xcode 2.1 could create universal binary files. It supported shared precompiled headers, unit testing targets, conditional breakpoints, and watchpoints. It also had a better dependency analysis.
The final version of Xcode for Mac OS X v10.4 was 2.5.
Xcode 3.0 was released with Mac OS X v10.5 “Leopard”. Notable changes since 2.1 include the DTrace debugging tool (now named Instruments), refactoring support, context-sensitive documentation, and Objective-C 2.0 with garbage collection. It also supports Project Snapshots, which provide a basic form of version control; Message Bubbles, which show build errors debug values alongside code; and building four-architecture fat binaries (32 and 64-bit Intel and PowerPC).
Xcode 3.1 was an updated release of the developer tools for Mac OS X and was the same version included with the iPhone SDK. It could target non-Mac OS X platforms, including iPhone OS 2.0. It included the GCC 4.2 and LLVM GCC 4.2 compilers. Another new feature since Xcode 3.0 is that Xcode’s SCM support now includes Subversion 1.5.
Xcode 3.2 was released with Mac OS X v10.6 “Snow Leopard” and installs on no earlier version of OS X. It supports static program analysis, among other features. It also drops official support for targeting versions earlier than iPhone OS 3.0. But it is still possible to target older versions, and the simulator supports iPhone OS 2.0 through 3.1. Also, Java support is “exiled” in 3.2 to the organizer.
Xcode 3.2.6 is the last version that can be downloaded for free for users of Mac OS X v10.6. Downloading it requires free registration at Apple’s developer site.
In June 2010, at the Apple Worldwide Developers Conference version 4 of Xcode was announced during the Developer Tools State of the Union address. Version 4 of the developer tools consolidate the Xcode editing tools and Interface Builder into one application, among other enhancements. Apple released the final version of Xcode 4.0 on March 9, 2011. The software was made available for free to all registered members of the $99 per year Mac Developer program and the $99 per year iOS Developer program. It was also sold for $4.99 to non-members on the Mac App Store (no longer available). Xcode 4.0 drops support for many older systems, including all PowerPC development and software development kits (SDKs) for Mac OS X 10.4 and 10.5, and all iOS SDKs older than 4.3. The deployment target can still be set to produce binaries for those older platforms, but for Mac OS platforms, one is then limited to creating x86 and x86-64 binaries. Later, Xcode was free to the general public. Before version 4.1, Xcode cost $4.99.
Xcode 4.1 was made available for free on July 20, 2011 (the day of Mac OS X Lion’s release) to all users of Mac OS X Lion on the Mac App Store. On August 29, 2011, Xcode 4.1 was made available for Mac OS X Snow Leopard for members of the paid Mac or iOS developer programs. Xcode 4.1 was the last version to include GNU Compiler Collection (GCC) instead of only LLVM GCC or Clang.
On October 12, 2011, Xcode 4.2 was released concurrently with the release of iOS 5.0, and it included many more and improved features, such as storyboarding and automatic reference counting (ARC). Xcode 4.2 is the last version to support Mac OS X 10.6 “Snow Leopard”, but is only available to registered developers with paid accounts; without a paid account, 3.2.6 is the latest download that appears for Snow Leopard.
Xcode 4.3, released on February 16, 2012, is distributed as one application bundle, Xcode.app, installed from the Mac App Store. Xcode 4.3 reorganizes the Xcode menu to include development tools. Xcode 4.3.1 was released on March 7, 2012, to add support for iOS 5.1. Xcode 4.3.2 was released on March 22, 2012, with enhancements to the iOS Simulator and a suggested move to the LLDB debugger versus the GDB debugger (which appear to be undocumented changes). Xcode 4.3.3, released on May 2012, featuring an updated SDK for Mac OS X 10.7.4 “Lion” and a few bug fixes.
Xcode 4.4 was released on July 25, 2012. It runs on both Mac OS X Lion (10.7) and OS X Mountain Lion (10.8) and is the first version of Xcode to contain the OS X 10.8 “Mountain Lion” SDK. Xcode 4.4 includes support for automatic synthesizing of declared properties, new Objective-C features such as literal syntax and subscripting, improved localization, and more. On August 7, 2012, Xcode 4.4.1 was released with a few bug fixes.
On September 19, 2012, iOS 6 and Xcode 4.5 were released. Xcode added support for iOS 6 and the 4-inch Retina Display on iPhone 5 and iPod touch 5th generation. It also brought some new Objective-C features to iOS, simplified localization, and added auto-layout support for iOS. On October 3, 2012, Xcode 4.5.1 was released with bug fixes and stability improvements. Less than a month later, Xcode 4.5.2 was released, with support for iPad Mini and iPad with Retina Display, and bug fixes and stability improvements.
On January 28, 2013, iOS 6.1 and Xcode 4.6 were released.
In June 2013, at the Apple Worldwide Developers Conference, version 5 of Xcode was announced. On September 18, 2013, Xcode 5.0 was released. It added support for iOS 7 SDK, with always support of OS X 10.8 Mountain Lion SDK but not the support of OS X 10.9 Mavericks SDK. This latest was only included in the betas version. It also added a version of Clang generating 64-bit ARM code for iOS 7. Apple removed support for building garbage collected Cocoa binaries in Xcode 5.1.
On June 2, 2014, at the Worldwide Developers Conference, Apple announced version 6 of Xcode. One of the most notable features was support for Swift, an all-new programming language developed by Apple. Xcode 6 also included features like Playgrounds and live debugging tools. On September 17, 2014, at the same time, iOS and Xcode 6 were released. Xcode could be downloaded on the Mac App Store.
On June 8, 2015, at the Apple Worldwide Developers Conference Xcode version 7 was announced. It introduced support for Swift 2, and Metal for OS X, and added support for deploying on iOS devices without an Apple Developer license. Xcode 7 was released on September 16, 2015.
On June 13, 2016 at the Apple Worldwide Developers Conference Xcode version 8 was announced. It introduced support for Swift 3. Xcode 8 was released on September 13, 2016.
On June 5, 2017, at the Apple Worldwide Developers Conference Xcode version 9 was announced. It introduced support for Swift 4 and Metal 2. It also introduced remotely debugging iOS and tvOS devices wirelessly through WiFi.
Xcode 9 was publicly released on September 19, 2017.
On June 4, 2018, at the Apple Worldwide Developers Conference, Xcode version 10 was announced; a beta version was released the same day. Xcode 10 introduced support for the Dark Mode announced for macOS Mojave, the collaboration platforms Bitbucket and GitLab (in addition to GitHub), training machine learning models from playgrounds, and the new features in Swift 4.2 and Metal 2.1, as well as improvements to the editor and the project build system. Xcode 10 also dropped support for building 32-bit macOS apps and no longer supports Subversion integration.
Xcode 10 was publicly released on September 17, 2018.
On June 3, 2019, at the Apple Worldwide Developers Conference, Xcode version 11 was announced; a beta version was released the same day. Xcode 11 introduced support for the new features in Swift 5.1, as well as the new SwiftUI framework (although the interactive UI tools are only available when running under macOS 10.15). It also supports building iPad applications that run under macOS; includes integrated support for the Swift Package Manager; and contains further improvements to the editor, including a “minimap” that gives an overview of a source code file with quick navigation. Xcode 11 requires macOS 10.14.4 or later.