Internal implementation package not meant for direct consumption. Please do not reference directly. Provides commonly-used classes for performing mathematical functions, conversions, string comparisons and querying environment information. Commonly Used Types: System.Math System.Environment System.Random System.Progress<T> System.Convert System.Diagnostics.Stopwatch System.Runtime.Versioning.FrameworkName System.StringComparer System.IO.Path When using NuGet 3.x this package requires at least version 3.4.