Apex Code

We’ve introduced a stub API to allow advanced developers to build their own mocking frameworks. We’ve also added diagnostic methods for Platform Cache and the ability to escape special characters in merge fields for Apex callouts that use named credentials. The Apex Test History page now shows the start date and time, and the number of failed and enqueued methods for the test run.
Available in: Enterprise, Performance, Unlimited, Developer, and Database.com Editions

For detailed information on these enhancements, refer to the Apex Developer Guide.