Not-so-Common Desktop Environment is a modern attempt at the style. I don't end up using it, but it reminds me wonderfully of a time when computers were made by and for people.
Uh, CDE was corporation-ware. The computers for the people and by the people used a hacked fvwm and rxvt making magic on Intel PC's with a Pentium I MMX /II running faster and snappier than even Irix and Sparc machines except for OpenGL.
CDE on Sun was a daily driver for my working life through the late 90's / early 2000's. KDE under Linux could be configured to have more or less the same UI semantics.
That changed with KDE 4 and a lot of people rejected it. One would assume those people are the same ones who now use Trinity.
https://github.com/NsCDE/NsCDE