SLiP is a quick, alternative syntax for creating and editing XML data by hand and if you know Python, it should also be familiar. not my cup of tea but has a nice comparison of other lightweight xml notations
PXSL – Parsimonious XML Shorthand Language PXSL ("pixel") is a convenient shorthand for writing markup-heavy XML documents. It provides XML authors and programmers with a simple, concise syntax that they can use to create XML documents. For more advanced users, PXSL offers customizable shortcuts and sophisticated refactoring tools like functional macros that can markedly reduce the size and complexity of markup-dense XML documents. The short version is this: PXSL is XML turned inside-out. Instead of tagging the structure, you tag the non-structure, which is the better approach when most of your information is structure.
xfpt is a program that reads a file of plain text that contains relatively simple markup, and outputs an XML file. It is intended to simplify the management of XML data. It is not a program that attempts to turn a plain text document into XML. Markup within text is introduced by ampersand characters, but is otherwise "soft". You can define what follows the ampersand, for example, &" to generate a "quote" element. There is also a macro facility that allows for higher level concepts such as chapters, displays, tables, etc.
A. Di Iorio, S. Peroni, and F. Vitali. Proceedings of the 17th international conference on Knowledge engineering and management by the masses, page 391--400. Berlin, Heidelberg, Springer-Verlag, (2010)