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

System.Xml.XPath.XDocument by: Microsoft

Provides extension methods that add System.Xml.XPath support to the System.Xml.XDocument package. Commonly Used Types: System.Xml.XPath.Extensions System.Xml.XPath.XDocumentExtensions

System.Xml.XPath.XmlDocument by: Microsoft

Provides extension methods that add System.Xml.XPath support to the System.Xml.XmlDocument package. Commonly Used Types: System.Xml.XPath.XmlDocumentExtensions

Utf8Json by: neuecc

Definitely Fastest and Zero Allocation JSON Serializer for C#(NET, .NET Core, Unity, Xamarin).