JStart gives the ability to start Java class files (or applets) by double clicking on them from the desktop like any executable program. You only have to assign *.class files to this program. It loads a class file, investigates it according to the Java Sun class file specification, extracts the full class name (including packages), and invokes the main method of that class.
Krusader is an advanced twin-panel (commander-style) file-manager for KDE 3.x, but with many extras. It provides all the file-management features you could possibly want. It also features extensive archive handling, mounted filesystem support, FTP, an advanced search module, a text viewer/editor, directory synchronization, support for file content comparisons, powerful batch renaming, and much more. It supports the following archive formats: tar, zip, bzip2, gzip, rar, ace, arj, and rpm. It can also handle other KIOSlaves such as smb:// or fish://.
GNU Midnight Commander is a text-mode full-screen file manager. It uses a two panel interface and a subshell for command execution. It includes an internal editor with syntax highlighting and an internal viewer with support for binary files. Also included is Virtual Filesystem (VFS), that allows files on remote systems (e.g. FTP servers) and files inside archives to be manipulated like real files.