Update _xctest.md

Author: fpseverino

documentation/core-libraries/_xctest.md

@@ -1,7 +1,11 @@
 ## XCTest
 
-The XCTest library is designed to provide a common framework for writing unit tests in Swift, for Swift packages and applications.
+The XCTest library provides a common framework for writing unit tests in Swift, for Swift packages and applications.
 
-This version of XCTest uses the same API as the XCTest you are familiar with from Xcode. Our goal is to enable your project's tests to run on all Swift platforms without having to rewrite them.
+This version of XCTest uses the same API as the XCTest you may be familiar with from Xcode. Our goal is to enable your project's tests to run on all Swift platforms without having to rewrite them.
+
+While XCTest remains supported, [Swift Testing](https://github.com/swiftlang/swift-testing) is the recommended framework for writing new tests. Swift Testing offers a modern, expressive, and extensible approach to testing in Swift, and represents the direction of future development.
+
+If you already have tests written using XCTest, you can run them side-by-side with newer tests written using Swift Testing.
 
 More information about XCTest on Linux is available on our [GitHub project page](http://www.github.com/swiftlang/swift-corelibs-xctest).