I finally figured out what was wrong with my applet: lwjgl could not find the native files. That was no problem to fix, just supply the directory to the files for your system (as stated in a lot of posts)
But: the tutorial suggests that the native files should be placed in jar-files (windows-native.jar, linux-native.jar, macos.jar)
When i try this in eclipse, im not allowed to set a jar as the "native libarary location". Is this possible?
how do i tell lwjgl where the native libraries are in an applet?