Is it possible to typeset mathematical equations using viki? I can't
find any reference to a math markup mode in the documentation.
If you mean with mathematical equations the latex environment of the same name, you'd have to define a custom region. If you mean mathematical stuff in general, you can use latex for this by means of the math macro.
For latex output, the latex markup is passed through. For html output, the latex snippets are rendered as images. Alternatively, you could use the html-asciimath, html-jsmath, or html-mathml modules. The inlatex-compound macro could also be of help.
http://deplate.sourceforge.net/Macros.html#hd0013005. See also: http://deplate.sourceforge.net/Modules.html#particleMath