This is repository with C# syntax highlighter for TeX (OPmac). The highlighter was made as part of semestral work for Typography and TeX course at FIT CTU.
You can see full documentation in english or in czech. The highlighter itself is in file cssyntax.tex.
You can paste whole macro into source document.
If you don't want to do this, you can just include file cssyntax.tex.
That can be done using \input cssyntax.
After inclusion of the macro you can use \hisyntax{CS} or \ghisyntax{CS} before verbatim to use highlighter locally or globally.
In source document the verbatim can look like this:
\hisyntax{CS}
\begtt
string foo = "bar";
...
\endtt