I am presently torturing myself with CDE. It's in FreeBSD's pkg repo and ports tree, and it provides a functional desktop, but it's too broken to be usable. The right-click menu is often incomplete, some tools crash and dump core, and Information Manager errors out with a configuration-related error message the 'Net has never written about.
That last one is sad because its command, dtinfo, runs just fine from the terminal emulator and reveals a complete and comprehensive help system library.
CDE was commercial software born in the Unix Wars, so it was expected to have an integrated online user-oriented manual. One that's complete, comprehensive, and written for the end user, accessible from a very lightweight hypertext browser utility, is a high standard programmers and technical writers should strive for even today.
