XML
The Extensible Markup Language (XML) is a general-purpose specification for creating custom markup languages.[1] It is classified as an extensible language because it allows its users to define their own elements. Its primary purpose is to facilitate the sharing of structured data across different information systems, particularly via the Internet,[2] and it is used both to encode documents and to serilize data. In the latter context, it is comparable with other text-based serialization languages such as JSON and YAML
XML > Forms
XForms - Repository for this next generation of Web forms, including implementations, mailing lists, working group, and relationship with other W3C work. (W3C Document Formats domain)
http://dbcdom.sourceforge.net/