lxt is a file manager program for Linux (and other Unix variants) that was inspired by the popular DOS program XTreeGold. Most of the keys are the same and the interface is similar but has been modified a bit to better suit Unix (eg. long file names and file permissions). Half of the code was written when I was in high school so don't judge me on the code quality (for example, I seem to have had something against whitespace at the time and global variables were my friend).
The most important hotkeys are:
The source code: lxt-1.3b.tar.gz