Web 2.0 is a trend in the use of World Wide Web technology and web design that aims to facilitate creativity, information sharing, and, most notably, collaboration among users. These concepts have led to the development and evolution of web-based communities and hosted services, such as social-networking sites, wikis, blogs, and folksonomies (the practice of catgorising content through tags). Although the term suggests a new version of the World Wide Web, it does not refer to an update to any technical specifications, but to changes in the ways software developers and end-users use the internet.

LINQ defines standard query operators that allow code written in LINQ-enabled languages to filter, enumerate, and create projections of several types of collections using the same syntax. Such collections may include arrays, enumerable classes, XML, datasets from relational databases, and third party data sources. The LINQ project uses features of version 2.0 of the .NET Framework, new LINQ-related assemblies, and extensions to the C# and Visual Basic .NET languages. Microsoft has distributed a preview release of LINQ, consisting of those libraries and compilers for C# 3.0 and Visual Basic 9. Other languages, such as F# and Nemerle, have also announced preliminary support.

Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.

An interpreting version of XSLT.

An XML look-alike for HTML defined by one of several XHTML DTDs. To use XHTML for everything would of course defeat the purpose of XML, because the idea of XML is to identify information content, and not just to tell how to display it. You can reference it in a DTD, which allows you to say, for example, that the text in an element can contain and tags rather than being limited to plain text.

XML documents. It differs from HTML, the markup language most often used to present information on the Internet. HTML has fixed tags that deal mainly with style or presentation. An XML document must undergo a transformation into a language with style tags under the control of a style sheet before it can be presented by a browser or other presentation mechanism. Two types of style sheets used with XML are CSS and XSL. Typically, XML is transformed into HTML for presentation. Although tags can be defined as needed in the generation of an XML document, a document type definition (DTD) can be used to define the elements allowed in a particular type of document. A document can be compared by using the rules in the DTD to determine its validity and to locate particular elements in the document. A Web services application's J2EE deployment descriptors are expressed in XML with schemas defining allowed elements. Programs for processing XML documents use SAX or DOM APIs.