Over the last couple of years I've been adding capabilities to use Trac as a preproduction tool. I had originally planned to use Celtx... but I have some issues with it the biggest of which was being unable to run my own servers. (Looking at their site just now while confirming the URL I see they've changed it quite a bit... but at this point Trac is working for me so I probably won't investigate again.)
For the most part Trac just kind of works for this task. A wiki is a pretty good structure for storing the information about a production. But there were some missing capabilities. One of the concerns was the ability to display scripts. At first I just needed to display script fragments... so I developed a Trac port of the scrippets Wordpress plug-in. It basically matched the format and gave the same capability as a Trac processor. But once I had that capability... another problem presented itself.
Final Draft is being used for creating the scripts. And it soon became clear that we needed a way for collaborators without Final Draft to view the scripts. The obvious solution was to extend the ScrippetMacro with the ability to parse and render Final Draft's fdx format. So I went ahead and implemented that along with a few other handy utilities like the ability to extract and display portions of fdx files and some other things of that nature. You can read about it on the [http://trac-hacks.org trac-hacks] page for the macro.
Another thing that's also come up is a desire to allow collaborators to avoid spoilers in the project notes. I hadn't actually planned on implementing anything fancy for this... we'd been using the span macro (Trac has ways to use spans as macros for doing simple text formatting not available to the wiki syntax) to set the foreground text color to white and had been accepting its limitations. I then saw a post about this on the trac-users mailing list and decided to give a go at implementing it. It ended up being a bit fancier than I had originally planned. If you're interested you can check it out here: SpoilerMacro
At the moment that's pretty much it on this front. I recently made some improvements to the scrippet macro to allow for a bit looser format and to handle Trac WikiFormatting a little better, but other than that it doesn't change much. The next big feature I might implement is to allow the inline markup to be exported as a fdx... but I haven't quite figured out how that would be managed yet.