Transact-SQL and XML, provides a declarative programming model, and lends itself to quick prototyping and deployment of robust notification applications. An API for creating subscription management applications is provided, plus standard components for collecting event data from files and SQL Server databases, for formatting notifications using XSLT, and for sending notifications via Simple Mail Transfer Protocol (SMTP) or by writing notifications to a file. If the standard components do not meet the needs of an application, Notification Services is extendable by building custom components using the .NET family of programming languages, such as Microsoft Visual C# .NET and Microsoft Visual Basic .NET. Finally, Notification Services can communicate with a wide variety of Microsoft, third-party, and custom-built event providers and delivery protocols, enabling Notification Services to communicate with existing systems in heterogeneous environments. See also Apple Push Notification Service Google Cloud Messaging Boomerang Software Framework References Further reading Microsoft SQL Server 2005 Notification Services, Shyam Pather, Sams Publishing, The Rational Guide to SQL Server Notification Services, Rational Press, External links Forums Microsoft Official Website TechNet Microsoft database software