Smaragd is a port of the Emerald window decoration engine to Plasma‘s window manager KWin. In other words, if you install Smaragd, you will be able to use Emerald themes for Compiz/Beryl in your Plasma desktop.
Smaragd was already released 6 years ago for KWin 4. Today, I have ported most of it to the new KDecoration2 API that KWin 5 uses. What is still missing is the configuration dialog, but you should be able to move the old kwinsmaragdrc file to ~/.config/ to keep your old settings.
(Install Cairo, GLIB2, KDecoration2, and KF5 devel packages) git clone git://anongit.kde.org/smaragd.git cd smaragd git checkout kdecoration2 mkdir build && cd build cmake -DCMAKE_INSTALL_PREFIX=/usr .. make && sudo make install (Logout and restart KWin)
To use Smaragd, you need to extract the *.emerald archive to ~/.emerald/theme/ (make sure the file ~/.emerald/theme/theme.ini exists after extracting). In the future, GHNS support will be added to ease installation.
Please report issues to bug.kde.org.