X Analyser Frequency spectrum analyzer and other sound-based apps
XastirX amateur station tracking and information reporting
xdiff X11/Motif based file comparator and merge tool
XEphem XEphem is a complete astronomy program written in Motif. It also includes a handy tooltip mechanism that requires no changes to existing widgets
xmcd Xmcd is a full-featured CD player utility package including xmcd, a CD player for the X Window system using the Motif graphical user interface and cda
XmNap XmNap is a Motif napster client. It supports chat, firewalled download and upload, hotlist and a limited set of privileged users