Applet didn't work for me here on linux since lwjgl_natives.jar wasn't found.
Anyway its a pretty simple problem, you can't read files from the file system when using applet, they have to be in the jars.
regnorm.jar does not contain "res\font\Calibri.ttf" hence it can't load it and fails after slick has checked the jar and then falls back to trying to look for it on the file system. You need to have that font file in your jar.
also I noticed that regnorm.jar oddly also contains both lwjgl.jar and slick.jar inside it, thats an extra 1.3mb that your applet doesn't need to function.
Well, f**k me! Sorry for my french, too. Let's hope the filter will catch that one.
I swear I had it. I'm going to rebuild that, and report back. I also don't know where I can get those. I usually just use Eclipse if I need to .jar something. Will the commandline work, with the linux natives provided in the official download?
I've now reuploaded too, and it still doesn't work. The error is the same though. Thanks for spotting, however.