[tristor]

This is a relatively accurate recollection. Each of the components of Seamonkey (which was the successor to Netscape, containing Navigator, Communicator, and others as you mentioned) was eventually rolled into a separate standalone project, some of which were part of the overall Mozilla Project and some which were done by the community outside of Mozilla. The IRC client even got spun out as ChatZilla as a standalone piece of software, as did the webpage editor/publisher (analogous to MS Front Page).