System.Security.Principal.Windows by: Microsoft

Provides classes for retrieving the current Windows user and for interacting with Windows users and groups. Commonly Used Types: System.Security.Principal.WindowsIdentity System.Security.Principal.SecurityIdentifier System.Security.Principal.NTAccount System.Security.Principal.WindowsPrincipal System.Security.Principal.IdentityReference System.Security.Principal.IdentityNotMappedException System.Security.Principal.WindowsBuiltInRole System.Security.Principal.WellKnownSidType

System.Text.Encoding by: Microsoft

Provides base abstract encoding classes for converting blocks of characters to and from blocks of bytes.

System.Threading.Timer by: Microsoft

Provides the System.Threading.Timer class, which is a mechanism for executing a method at specified intervals. Commonly Used Types: System.Threading.Timer System.Threading.TimerCallback

System.Xml.XPath by: Microsoft

Provides the classes that define a cursor model for navigating and editing Extensible Markup Language (XML) information items as instances of the XQuery 1.0 and XPath 2.0 Data Model. Commonly Used Types: System.Xml.XPath.XPathNavigator System.Xml.XPath.IXPathNavigable System.Xml.XPath.XPathNodeType System.Xml.XPath.XPathNodeIterator System.Xml.XPath.XPathExpression System.Xml.XPath.XPathResultType System.Xml.XPath.XPathException System.Xml.XPath.XPathDocument System.Xml.XPath.XPathItem System.Xml.XPath.XPathNamespaceScope

xunit by: jnewkirk, bradwilson

xUnit.net is a developer testing framework, built to support Test Driven Development, with a design goal of extreme simplicity and alignment with framework features. Installing this package installs xunit.core, xunit.assert, and xunit.analyzers.