Free suite of software development tools developed by Apple

Xcode for Mac

Xcode for Mac

  -  Freeware
Xcode for Mac includes everything you need to create amazing apps for all Apple platforms. Now Xcode and Instruments look great in the new Dark Mode on macOS Mojave. The source code editor lets you transform or refactor code more easily, see source control changes alongside the related line, and quickly get details on upstream code differences. You can build your own instrument with custom visualization and data analysis. Swift compiles software more quickly, helps you deliver faster apps, and generates even smaller binaries. Test suites complete many times faster, working with a team is simpler and more secure, and much more.

Code you write in Xcode looks stunning as the dark X code interface makes your work the star of the show. The entire interface is tuned for your dark Mac experience, from icons, to fonts, to the subtle contrast color of the Jump Bar.

It also gives you powerful tools for creating your own dark apps for macOS. Interface Builder lets you quickly switch your design and preview from light to dark. Asset catalogs define assets and named colors. And you can switch your app in and out of Dark Mode while debugging. This is all done using controls within the tool that only apply to your app. No need to change your system settings.

The app includes a lightning-fast source code editor. Text scrolls incredibly smoothly, even when editing enormous source files. Smooth animations are used throughout, whether folding your code to enhance focus, or when X code highlights errors and offers Fix-its. With great Markdown support, your accompanying documentation will look great, too.

Source control is the place where your whole team works on code together. Apple Xcode supports working directly with several collaboration platforms, including:
  • GitHub and GitHub Enterprise
  • Bitbucket Cloud and Bitbucket Server
  • GitLab.com and GitLab self-hosted
It's never been easier for your team to work together in the cloud or on self-hosted servers within your organization. To make your workflows easier and more secure, Xcode for macoS can even generate a unique SSH key for you and upload it to the server.

Using Instruments, you can finally retire your print() statements, which are replaced with OSLog signposts and your own custom instruments. With virtually no overhead you can mark important points throughout your code, then track those signposts as your app runs in Instruments. These log points appear alongside other analysis events such as CPU, memory, or network usage to give you valuable insights into your code’s behavior.

It includes a robust testing engine built right in. Run unit tests, as well as UI and performance tests, across multiple physical devices at a time. Or take advantage of the processing horsepower of Mac to dramatically speed up testing using simulated devices running in parallel.

It includes Swift 4.2, which compiles your software more quickly, helps you deliver faster apps, and generates even smaller binaries. Compared to Swift 4.0, the latest Swift compiler can build large apps more than twice as fast.* Combined with the new Xcode new build system, your everyday edit, build, and test workflow is much faster. Optimized for the latest multi-core Mac hardware, the app and Swift make for a lightning-fast development platform.

Swift was built to be fun to use, and it’s easy to experiment with an API when using a playground file. In Apple X code, playgrounds are dramatically enhanced to work more like a traditional REPL, while making the live view even more responsive and fun to use for quick designs. As you add new code, only new lines are recompiled. You can choose to re-run specific lines of code, or hit shift-return to run the program right up to the line of code you just typed.

Features and Highlights
  • Built-in interface builder
  • iOS simulator
  • Integrated build system
  • Instrument library
  • Compilers
  • Graphical debugger
  • Built-in assistant editor
  • Data recorder
  • Source editor
  • Visual comparison
  • Zombie detection
  • Static analysis
  • Source viewer
  • Organizer
  • Low-overhead sampling
  • Refactoring
  • Customizable instruments
  • Built-in version editor
  • System trace


  • Xcode 16.2 Screenshots

    The images below have been resized. Click on them to view the screenshots in full size.

    Xcode 16.2 Screenshot 1
  • Xcode 16.2 Screenshot 2

What's new in this version:

Xcode 16.2
- Xcode 16.2 includes Swift 6 and SDKs for iOS 18.2, iPadOS 18.2, tvOS 18.2, watchOS 11.2, visionOS 2.2, and macOS Sequoia 15.2


Xcode 16.1
- Xcode 16.1 includes Swift 6 and SDKs for iOS 18.1, iPadOS 18.1, tvOS 18.1, watchOS 11.1, visionOS 2.1, and macOS Sequoia 15.1
- This update provides bug fixes and improved stability, and adds support for installing individual simulator runtimes using the xcodebuild command line tool


Xcode 16.0
- Predictive code completion boosts your productivity when writing Swift code, using a code intelligence model that keeps your code private and works even when you’re offline
- Swift 6 makes it even easier to write safe concurrent code with a new language mode that analyzes your code at compile-time and diagnoses possible data races
- Swift Testing simplifies writing tests with features like parameterization to run the same test over a series of values, and tags to flexibly organize your tests
- Previews can share environments or data across your app and use property wrappers within preview blocks
- Explicit Modules provides better build parallelism, better diagnostics, and faster debugging
- Unified backtrace view shows relevant code from all stack frames in a single view
- Thread Performance Checker surfaces runtime issues and performance problems, including diagnostics to identify excessive disk writes
- RealityKit Debugger captures snapshots of a running visionOS app entity hierarchy to explore it in 3D


Xcode 15.4
- Xcode 15.4 includes Swift 5.10 and SDKs for iOS 17.5, iPadOS 17.5, tvOS 17.5, watchOS 10.5, visionOS 1.2, and macOS Sonoma 14.5
- This update provides bug fixes and improved stability


Xcode 15.3
- Xcode 15.3 includes Swift 5.10 and SDKs for iOS 17.4, iPadOS 17.4, tvOS 17.4, watchOS 10.4, visionOS 1.1, and macOS Sonoma 14.4
- This update provides bug fixes and improved stability, along with features like the ability to create a screenshot of the preview canvas directly from the Editor menu.


Xcode 15.2
- Xcode 15.2 includes Swift 5.9 and SDKs for iOS 17.2, iPadOS 17.2, tvOS 17.2, watchOS 10.2, visionOS, and macOS Sonoma 14.2
- This update adds support for the visionOS SDK to create apps for Apple Vision Pro


Xcode 15.1
- Xcode 15.1 includes Swift 5.9 and SDKs for iOS 17.2, iPadOS 17.2, tvOS 17.2, watchOS 10.2, and macOS Sonoma 14.2
- This update adds support for manually triggering Xcode Cloud workflows


Xcode 15.0.1
- Xcode 15.0.1 includes Swift 5.9 and SDKs for iOS 17, iPadOS 17, tvOS 17, watchOS 10, and macOS Sonoma
- This update fixes an issue that could extend the Simulator launch time when executing a test, and provides improved stability


Xcode 14.5
- Swift macro support brings inline expansions and breakpoint debugging in the source editor
- Git staging helps craft your next commit without leaving your code
- String catalogs streamline localization with a single place to view and edit strings
- Bookmarks help organize your favorite locations and searches in your projects
- Test reports provide summary view, testing insights, and video playback for UI automation results
- OSLog offers a structured and customizable logging mechanism in the debug console
- Documentation Preview editor brings real-time preview for DocC content
- Archive workflows streamline distribution with simplified export and upload to TestFlight and the App Store


Xcode 14.3.1
- This update fixes an issue that could prevent development when targeting devices running iOS 13
- Xcode 14.3.1 includes Swift 5.8.1 and SDKs for iOS 16.4, iPadOS 16.4, tvOS 16.4, watchOS 9.4, and macOS Ventura 13.3


Xcode 14.3
- Xcode 14.3 includes Swift 5.8 and SDKs for iOS 16.4, iPadOS 16.4, tvOS 16.4, watchOS 9.4, and macOS Ventura 13.3


Xcode 14.2
- Xcode 14.2 includes SDKs for iOS 16.2, iPadOS 16.2, tvOS 16.1, watchOS 9.1, and macOS Ventura 13.1


Xcode 14.1
- Xcode 14.1 includes SDKs for iOS 16.1, iPadOS 16.1, tvOS 16.1, watchOS 9.1, and macOS Ventura


Xcode 14.0.1
Xcode:
- Downloadable simulator runtime for watchOS and tvOS
- Single target template for multi-platform apps across iOS, iPadOS, macOS, and tvOS
- Asset catalog generates all icons sizes from a single 1024*1024 source image
- Pinned code structure in source editor
- SwiftUI Previews are interactive by default and provides multiple UI variations from a single PreviewProvider

Build and Documentation:
- Build system uses improved dependencies analysis and parallelism for faster performance
- New assistant editor to help identify build performance issues
- Build and command package plug-ins in Swift Packages
- Swift-DocC supports writing and building documentation for Objective-C and C APIs

Swift:
- Syntax highlighting and refactoring operations for regular expressions
- Smarter code completion and additional dynamic snippets


Xcode 14.0
- Xcode 14 includes Swift 5.7 and SDKs for iOS 16, iPadOS 16, tvOS 16, watchOS 9, and macOS Monterey 12.5

Xcode:
- Downloadable simulator runtime for WatchOS and tvOS
- Single target template for multi-platform apps across iOS, iPad OS, macOS, and tvOS
- Automatic icon generation for all icon sizes using the Asset Catalog
- Pinned code structure in source editor
- Interactive SwiftUI Previews are now on by default and provide multiple UI variations from a single PreviewProvider

Build and Documentation
- Faster build performance using improved dependency analysis and increased parallelism
- New build timeline assistant to help identify build performance issues
- Build and command package plug-ins in Swift Packages
- Objective-C and C API documentation support in Swift-DocC

Swift
- Syntax highlighting and refactoring operations for regular expressions
- Smarter code completion and additional dynamic snippets


Xcode 13.4.1
- Xcode 13.4.1 includes SDKs for iOS 15.5, iPadOS 15.5, tvOS 15.4, watchOS 8.5, and macOS Monterey 12.3, and bug fixes


Xcode 13.4
- Xcode 13.4 includes SDKs for iOS 15.5, iPadOS 15.5, tvOS 15.4, watchOS 8.5, and macOS Monterey 12.3, and bug fixes


Xcode 13.3.1
Xcode 13.3.1 includes SDKs for iOS 15.4, iPadOS 15.4, tvOS 15.4, watchOS 8.5, and macOS Monterey 12.3, and bug fixes including the following:
- bitcode_strip tool may cause apps built with bitcode to crash on launch


Xcode 13.3
Xcode 13.3 includes SDKs for iOS 15.4, iPadOS 15.4, tvOS 15.4, watchOS 8.5, and macOS Monterey 12.3, along with other features and bug fixes:
- Swift Package Manager enables extensible build tools and custom command plugins
- Xcode Account integration adds Ed25519 encryption support for SSH keys


Xcode 13.2.1
Fixed:
- Apps built with Swift concurrency may crash on launch
- Xcode was unable resolve Swift packages


Xcode 13.2
- Support for Swift Playgrounds 4 app projects
- Xcode Organizer displays smart insight notifications for monitoring power and performance in your app
- Swift Concurrency is available for apps that deploy to iOS 13, iPad OS 13, tvOS 13, watchOS 6, and macOS 10.15 or newer
- TextureConverter adds support for error metrics, decompressing textures at build time, and skipping compression when output textures are up-to-date
- Additional bug fixes and stability improvements


Xcode 13.1
- Xcode 13.1 includes Swift 5.5 and SDKs for iOS 15, iPad OS 15, tvOS 15, watchOS 8, and macOS Monterey

New:
- Support for macOS Monterey
- Additional bug fixes and stability improvements


Xcode 13.0
Xcode 13 includes Swift 5.5 and SDKs for iOS 15, iPadOS 15, tvOS 15, and watchOS 8:
- Swift adds support for concurrency, improved type inference, and faster incremental builds
- Pull request workflow lets you view and create pull requests in Xcode
- Code review comments with the name and avatar of the commenter are integrated in the editor
- Xcode organizer displays Test Flight crash reports dramatically faster
- Swift package collections help you find and integrate Swift packages in your own apps
- Swift Docc builds documentation for your Swift framework or package directly from your source code’s documentation comments
- Quick compare lets you compare any two versions of your source code in any editor
- Vim mode in the editor supports common vim key combinations and editing modes
- Simulator now includes CarPlay support with control over screen size, resolution, and variable input methods
- Additional bug fixes and stability improvements


Xcode 12.5.1
- Addresses a stability issue related to opening the Organizer window
- Fixed an issue where XCTest code wasn't generated after pressing the Record button
- Additional bug fixes and stability improvements


Xcode 12.5
- Playgrounds documents can access symbols within the current app target
- Simulator can record videos of your app and export the video as an animated GIF
- Swift improves incremental build time performance
- watchOS apps gain improved support for automated testing
- Localization workflow can export all projects within a workspace into a single catalog
- Code signing performance is improved for complex projects
- Additional bug fixes and stability improvements


Xcode 12.4
- Xcode 12.4 supports iOS 14.4, iPadOS 14.4, tvOS 14.4, watchOS 7.3, and macOS Big Sur 11.2

New in Xcode 12.4:
- Fixed an issue that prevented debugging iPhone or iPad apps running on an M1-powered Mac
- Additional bug fixes and stability improvements


Xcode 12.3
- Change log not available for this version


Xcode 12.2
New:
- Xcode IDE adopts the refined macOS Big Sur design including updated toolbar, icons, and sidebar
- Mac apps are updated to Universal, and Macs with Apple silicon can debug both the Apple silicon and Intel versions
- Multiplatform template generates a single project with shared SwiftUI code across iOS, iPadOS, and macOS apps
- Mac Catalyst projects can use the Mac idiom to take total control of the app’s interface using native scale
- When run on a Mac with Apple silicon, Xcode can test and debug iPhone and iPad apps as they run on macOS

Additional features:
- Document tabs open any type of document in a lightweight editor tab, including logs, asset catalogs, and UI files
- StoreKit testing framework and transaction manager make it easy to test and debug in-app purchases
- Navigator fonts are now resizable based on the system setting, or can be manually configured
- Organizer is completely redesigned, and reports new app metrics such as hitches in animation and scrolling
- SwiftUI Views can be turned into reusable components that appear in the Xcode library and in code completions


Xcode 12.1
Platform features:
- App Clips are a small part of your app that’s discoverable at the moment it’s needed, loads in seconds, and launches quickly
- WidgetKit uses SwiftUI to build beautiful new widgets that users can install directly on their iPhone home screen
- StoreKit testing framework and transaction manager make it easy to test and debug in-app purchases

Refined user interface:
- Document tabs open any type of document in a lightweight editor tab, including logs, asset catalogs, and UI files
- Navigator fonts are now resizable based on the system setting, or can be manually configured
- Code completion has a new, simplified interface that is faster, and makes it easier to choose the correct code
- Organizer is completely redesigned, and reports new app metrics such as hitches in animation and scrolling

Swift and SwiftUI:
- Performance for SwiftUI has been improved throughout, and new Lazy views can efficiently handle enormous data sets
- SwiftUI Views can be turned into reusable components that appear in the Xcode library and in code completions
- Swift Package Manager supports resources and localizations, making it great for sharing SwiftUI components
- Swift compiler’s improved diagnostics make it much easier to understand coding mistakes, especially in SwiftUI code


Xcode 12.0.1
- Xcode 12 includes Swift 5.3 and SDKs for iOS 14, iPadOS 14, tvOS 14, watchOS 7, and macOS Catalina

Platform features:
- App Clips are a small part of your app that’s discoverable at the moment it’s needed, loads in seconds, and launches quickly
- WidgetKit uses SwiftUI to build beautiful new widgets that users can install directly on their iPhone home screen
- StoreKit testing framework and transaction manager make it easy to test and debug in-app purchases

Refined user interface:
- Document tabs open any type of document in a lightweight editor tab, including logs, asset catalogs, and UI files
- Navigator fonts are now resizable based on the system setting, or can be manually configured
- Code completion has a new, simplified interface that is faster, and makes it easier to choose the correct code
- Organizer is completely redesigned, and reports new app metrics such as hitches in animation and scrolling

Swift and SwiftUI:
- Performance for SwiftUI has been improved throughout, and new Lazy views can efficiently handle enormous data sets
- SwiftUI Views can be turned into reusable components that appear in the Xcode library and in code completions
- Swift Package Manager supports resources and localizations, making it great for sharing SwiftUI components
- Swift compiler’s improved diagnostics make it much easier to understand coding mistakes, especially in SwiftUI code


Xcode 11.7
- New Exposure Notification APIs provide additional information about potential exposures


Xcode 11.6
- DriverKit API enhancements in the macOS SDK
- Additional bug fixes and stability improvements


Xcode 11.5
- Supports the Exposure Notification API
- Bug fixes and stability improvements


Xcode 11.4.1
- Bug fixes and stability improvements


Xcode 11.4
- Xcode 11.4 supports developing apps for iOS 13.4, iPadOS 13.4, tvOS 13.4, watchOS 6.2, and macOS Catalina 10.15.4
- Interface Builder and Simulator work with the new cursor support in iPadOS
- MacOS projects now support App Store universal purchase
- Simulator can trigger remote push notifications
- Tests written in Swift report the location in your code where errors originated and then highlight the line
- Additional bug fixes and stability improvements


Xcode 11.3.1
- Xcode 11.3.1 supports developing apps for iOS 13.3, iPadOS 13.3, tvOS 13.3, watchOS 6.1.1, and macOS Catalina 10.15.2
- Addresses a bug in the storyboard canvas that could cause Xcode to crash
- Additional bug fixes and stability improvements


Xcode 11.3
- Adds simulator support for Touch Bar (2nd generation)
- Additional bug fixes and stability improvements


Xcode 11.2.1
- Xcode 11.2.1 includes Swift 5.1 and SDKs for iOS 13.2, iPadOS 13.2, tvOS 13.2, watchOS 6.1, and macOS Catalina 10.15.1
- This update fixes a critical issue that could cause apps using UITextView to crash


Xcode 11.2
- Xcode 11.2 includes Swift 5.1 and SDKs for iOS 13.2, iPadOS 13.2, tvOS 13.2, watchOS 6.1, and macOS Catalina 10.15.1


Xcode 11.1
- Xcode 11.1 includes Swift 5.1 and SDKs for iOS 13.1, iPadOS 13.1, tvOS 13, watchOS 6, and macOS Catalina 10.15

SwiftUI:
- SwiftUI framework and design tools work together to enable a new way to build user intefaces
- Declarative syntax defines your user interface using easy-to-read Swift code
- Design tools make it as easy as drag-and-drop to construct and edit your views
- Code you write is always in sync with the design and preview canvas
- Library of controls and modifiers make it easy to build complex interfaces
- Animations are built using simple commands that describe the action you want to see
- Preview your real app running on multiple device types, orientations, and font sizes
- Share common code across all Apple platforms, and add custom experiences for each OS

Mac Catalyst brings iPad apps to the Mac:
- Click a single checkbox in your iPad project to add a native Mac app
- One project and set of source code creates iPhone, iPad, and Mac versions of your app
- Customize elements of your app for an experience unique to Mac
- Add new SwiftUI code to your project along side existing UIKit code
- Submit to the Mac App Store or notarize for outside distribution

Swift and Swift Packages:
- Swift packages are supported throughout, including build, debug, and SCM workflows
- Use Swift packages from GitHub, Bitbucket, GitLab, or your own hosts
- Download packages automatically based on dependency analysis
- Create your own packages to share code among all your apps, or to publish for the community

iOS dark mode:
- Switch between light and dark mode instantly while developing and debugging
- Asset catalog makes it easy to control images and colors for dark and light mode

Editor:
- Editor minimap gives a bird’s eye view of your code so you can quickly jump to any line
- Each editor view has its own preview, assistant, or other complementary views
- Split any editor pane to layout your workspace exactly as you want

Other improvements:
- Build stand-alone watchOS apps with a faster debugging experience
- Simulator launches quickly and uses the GPU to accelerate Metal code
- Test plans give you greater control of your test harness with sharable results bundles
- Automatically generate localized screenshots using UI tests as part of your test plan
- Source control adds support for stash and cherry-pick operations
- Simulate device conditions such as a slow network or thermal warnings while debugging
- Metrics tab in the Organizer shows how efficiently your app runs on customer devices


Xcode 11.0
- Xcode 11 includes Swift 5.1 and SDKs for iOS 13, tvOS 13, watchOS 6, and macOS Catalina 10.15

SwiftUI:
-  SwiftUI framework and design tools work together to enable a new way to build user intefaces
-  Declarative syntax defines your user interface using easy-to-read Swift code
-  Design tools make it as easy as drag-and-drop to construct and edit your views
-  Code you write is always in sync with the design and preview canvas
-  Library of controls and modifiers make it easy to build complex interfaces
-  Animations are built using simple commands that describe the action you want to see
-  Preview your real app running on multiple device types, orientations, and font sizes
-  Share common code across all Apple platforms, and add custom experiences for each OS
- NOTE: SwiftUI requires iOS 13, watchOS 6, tvOS 13, or macOS Catalina. To use the SwiftUI design canvas Xcode 11 must be running on macOS Catalina, coming this Fall

Mac Catalyst brings iPad apps to the Mac:
- Click a single checkbox in your iPad project to add a native Mac app
- One project and set of source code creates iPhone, iPad, and Mac versions of your app
- Customize elements of your app for an experience unique to Mac
- Add new SwiftUI code to your project along side existing UIKit code
- Submit to the Mac App Store or notarize for outside distribution

Swift and Swift Packages:
-  Swift packages are supported throughout, including build, debug, and SCM workflows
-  Use Swift packages from GitHub, Bitbucket, GitLab, or your own hosts
-  Download packages automatically based on dependency analysis
-  Create your own packages to share code among all your apps, or to publish for the community

iOS dark mode:
- Switch between light and dark mode instantly while developing and debugging
- Asset catalog makes it easy to control images and colors for dark and light mode

Editor:
-  Editor minimap gives a bird’s eye view of your code so you can quickly jump to any line
-  Each editor view has its own preview, assistant, or other complementary views
-  Split any editor pane to layout your workspace exactly as you want

Other improvements:
- Build stand-alone watchOS apps with a faster debugging experience
- Simulator launches quickly and uses the GPU to accelerate Metal code
- Test plans give you greater control of your test harness with sharable results bundles
- Automatically generate localized screenshots using UI tests as part of your test plan
- Source control adds support for stash and cherry-pick operations
- Simulate device conditions such as a slow network or thermal warnings while debugging
- Metrics tab in the Organizer shows how efficiently your app runs on customer devices


Xcode 10.3
- Xcode 10.3 includes SDKs for iOS 12.4, tvOS 12.4, watchOS 5.3, and macOS Mojave 10.14.6


Xcode 10.2.1
- Xcode 10.2.1 fixes a build time issue in large Swift projects, and includes additional bug fixes

Swift 5:
- Swift 5 runtime is included as part of the OS in the latest Apple platform releases
- App Store thins the Swift runtime from your apps for faster downloads to devices running latest OS
- SIMD vector types are built into the standard library
- String literals have an enhanced syntax that makes them easier to read and write
- New Result enum type makes it easier to handle errors across asynchronous operations

Other enhancements in Xcode:
- Debugger console has a new frame variable command alias “v” that is faster than “p” or “po”
- Playgrounds include various stability improvements and additional memory safety checks


Xcode 10.2
- Xcode 10.2 includes Swift 5 and SDKs for iOS 12.2, tvOS 12.2, watchOS 5.2, and macOS Mojave 10.14.4

Swift 5:
- Swift 5 runtime is included as part of the OS in the latest Apple platform releases
- App Store thins the Swift runtime from your apps for faster downloads to devices running latest OS
- SIMD vector types are built into the standard library
- String literals have an enhanced syntax that makes them easier to read and write
- New Result enum type makes it easier to handle errors across asynchronous operations

Other enhancements in Xcode:
- Debugger console has a new frame variable command alias “v” that is faster than “p” or “po”
- Playgrounds include various stability improvements and additional memory safety checks
- Additional bug fixes


Xcode 10.1
- Xcode 10.1 includes Swift 4.2.1 and SDKs for iOS 12.1, watchOS 5.1, tvOS 12.1, and macOS Mojave

Dark mode in macOS Mojave:
- All-new dark appearance throughout Xcode and Instruments
- Asset catalogs add dark and light variants to customize colors and image assets
- Interface Builder easily switches between dark and light variants of the app's interface
- Debugger switches Mac apps between dark and light variants without changing OS settings

Source control:
- Code that differs from the repository server is highlighted directly within the editor, including:
- Local changes not yet pushed to the shared repository
- Upstream changes others have made
- Conflicts to address before committing
- Account integration with self-hosted and cloud servers from Atlassian Bitbucket, GitLab, and GitHub
- Account logins generate SSH keys on-demand and upload to the service provider
- Rebase is an option when pulling the latest version of code

Editor enhancements:
- Multiple cursors in the editor enable many changes at once
- Code folding ribbon can hide any code block surrounded by braces
- Over-scroll makes it easy to display the last lines of code in the center of the screen

Playgrounds and machine learning:
- Completely redesigned REPL-like playgrounds are much faster and more stable
- Run code at any time by hitting SHIFT-RETURN or click the inline Run button to execute to a specific line
- Interactively train and exercise new Create ML models directly within a playground

Test and debug:
- Debug symbols download from a device 5x faster than before
- Tests run in parallel across many Simulators to take full advantage of all CPU cores
- Custom instruments provide unique data visualization for any code
- Memory debugger layout is redesigned to make it easier to navigate and visualize the whole app
- Metal shader debugger inspects the execution of vertex, fragment, compute, and tile shader code
- Metal dependency viewer shows a detailed graph of how resources are used

Build Performance:
- New build system improves performance and is enabled by default for all projects
- Swift compiles each individual file significantly faster, and greatly improves incremental builds


Xcode 10.0
- Xcode 10 includes Swift 4.2 and SDKs for iOS 12, watchOS 5, tvOS 12, and macOS Mojave