pekwm is a lightweight and unobtrusive window manager. Simple, minimalist, and still under development.
I've built pekwm for Solaris and made the packages available.
There's one change to the source: grep for /bin/sh in
src/*.cc and replace it with
/usr/xpg4/bin/sh.
These packages have the pekwm binary stripped, which reduces its size by a factor of 25 or more.
Choose the right file from the following list:
To install,
pkgadd -d PCTpekwm.i386.pkg PCTpekwm
where you should replace "PCTpekwm.i386.pkg" with whichever file you downloaded.
Note that the default configuration is very minimalist. All you get is a blank screen, with just a right-click menu.
(Using pkgadd should work on OpenSolaris distributions too. You can safely ignore any conflicts marked as "attribute change only". And binary compatibility should ensure that the software works correctly as well.)
There are also some pekwm themes on box-look.