The document outlines Microsoft's .NET development platform and roadmap. It discusses how .NET is intended as a unified platform for building desktop, web, cloud and mobile applications. It provides release dates for upcoming versions of .NET Core from 2019 to 2023, including which will be long-term support releases. It also previews new features for .NET 5 like Span<T>, IAsyncEnumerable<T>, and hardware intrinsics, as well as changes like dropping support for some APIs in the full .NET Framework. Finally, it confirms Windows desktop frameworks like Windows Forms and WPF will continue to be supported and developed openly.