I'm sorry, but I still don't understand exactly what you want. Do you mean you want syntax highlighted code snippets, the way that our code snippets have line numbers, etc? Or do you want people to be able to type in code snippets? Is the screenshot you provided what you're looking for, because I'm pretty sure that would be something like CodeMirror.
I've used syntax highlighter before, see this link. video tutorial on that page. There are a lot of different highlighters out there on the net that you can choose from...some better than others for what you need.