Personally, I'm very fond of spod5, which takes plain pod and converts it into an S5 slideshow, which can easily be displayed through IE or FireFox (press F11 for full-screen/kiosk mode). There are some other S5 modules that also produce these slideshows.
One option that no one seems to have mentioned yet is LaTeX; as an aficionado I'll do: there are many packages to write talks. A very popular choice currently is beamer with pdf output. I made my own thesis presentation with it and it was easy and straightforward. I have temporarily uploaded an example. (Please note that this is a preliminary version of the talk, it even contains an actual error, and for some reason I don't have the definitive one on this machine nor can I currently access it otherwise so the link is not going to work long.) Just consider that I stayed KISS, but you can do more complex things if you wish. Anyway you produce a simple pdf file that can be displayed with quite about any common viewer. With Acrobat Reader, and I suspect others, if you open it standalone as opposed to in a browser's window, it will automatically go full screen.
Now, my presentation didn't contain code, but for code listings the very popular choice is the listings package: I've not used it in connection with beamer nor any other presentation package and I am not aware of how they will interact, but I don't expect any particular problem. Anyway I know people do create presentations in LaTeX containing code, so some way or another it is certainly possible.
Update: I just tested the link I posted above and for some reason it doesn't seem to work, well at least with Firefox: the file gets truncated at some time. I downloaded it with wget and I get the whole file. I suspect there are some problems with the perlmonk.org hosting a few fellow monks are kindly offering us.