FileRunner is a two pane filemanager for Unix and Unix like systems. It is simple and efficient and has a built-in FTP and SFTP client. It also does a reasonable (and improving) job on Windows systems. New and improved from a FileRunner of long ago.
EU-Commander is an Tcl/Tk based filemanager (WinCommander like) with applications bar, favorites, mime types. Additional modules (e.g. text/picture viewer/editor) and some more are included in the package. Easy implementation of own Tcl/Tk modules.