Use google Prettify for syntax highlighting instead of CodeRay
I believe it would be preferrable to use the google prettify syntax highlighter rather than Coderay for syntax highlighting in Redmine.
I have hacked support for this into our redmine installation, and the necessary changes (if letting coderay stay active as well) are minimal.
Now, I'm not a rails coder, so the following step is probably not the cleanest solution. I'll describe it anyway for completeness:
3. Modify app/views/layouts/base.rhtml with the following changes: 3.1. add onload="prettyPrint()" to the body tag. 3.2. link to prettify.js and prettify.css in the header. 4. Put code in pre blocks with class "prettyprint".