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
Haml takes your gross, ugly templates and replaces them with veritable Haiku. Haml is the next step in generating views in your Rails application. Haml is a refreshing take that is meant to free us from the shitty templating languages we have gotten used to. Haml is based on one primary principal. Markup should be beautiful. Haml is a real solution to a real problem. Stop using the slow, repetitive, and annoying templates that you don’t even know how much you hate yet
"HAML (short for XHTML Abstraction Markup Language) expresses HTML in an outline form, while SaSS (an acronym for Syntactically Awesome StyleSheets) does the same for CSS. Both provide conveniences such as macros and expressions, and structure is implied with active white space (a la Python). You can also embed code in outline form: no blocks required."