System.Runtime by: Microsoft

Provides the fundamental primitives, classes and base classes that define commonly-used value and reference data types, events and event handlers, interfaces, attributes, and exceptions. This packages represents the core package, and provides the minimal set of types required to build a managed application. Commonly Used Types: System.Object System.Exception System.Int16 System.Int32 System.Int64 System.Enum System.String System.Char System.Boolean System.SByte System.Byte System.DateTime System.DateTimeOffset System.Single System.Double System.UInt16 System.UInt32 System.UInt64 System.IDisposable System.Uri When using NuGet 3.x this package requires at least version 3.4.

System.Runtime.InteropServices.RuntimeInformation by: Microsoft

Provides APIs to query about runtime and OS information. Commonly Used Types: System.Runtime.InteropServices.RuntimeInformation System.Runtime.InteropServices.OSPlatform When using NuGet 3.x this package requires at least version 3.4.

System.Text.Encoding.CodePages by: Microsoft

Provides support for code-page based encodings, including Windows-1252, Shift-JIS, and GB2312. Commonly Used Types: System.Text.CodePagesEncodingProvider

System.Text.RegularExpressions by: Microsoft

Provides the System.Text.RegularExpressions.Regex class, an implementation of a regular expression engine. Commonly Used Types: System.Text.RegularExpressions.Regex System.Text.RegularExpressions.RegexOptions System.Text.RegularExpressions.Match System.Text.RegularExpressions.Group System.Text.RegularExpressions.Capture System.Text.RegularExpressions.MatchEvaluator When using NuGet 3.x this package requires at least version 3.4.

System.Threading.Tasks by: Microsoft

Provides types that simplify the work of writing concurrent and asynchronous code. Commonly Used Types: System.Threading.Tasks.Task<TResult> System.Runtime.CompilerServices.TaskAwaiter<TResult> System.Threading.Tasks.TaskCompletionSource<TResult> System.Threading.Tasks.Task System.OperationCanceledException System.AggregateException

Xamarin.Build.Download by: Xamarin Inc.

Support for downloading and unpacking archives when building MSBuild projects