Experimental Physics and
Industrial Control System

Although your initial email was calling for a widget toolkit to replace edm, you may find that workspace management can be done with a combination of tools: GUI framework, window manager, and window matching utility.

For windows management, we are also using wmctl and devilspie.
We use wmctl for initial population of workspaces (go to workspace 1, open applications, go to workspace 2, open applications, ...)

A more sophisticated tool you may want to look at is devilspie, a window matching utility.
Window matching utilities can run from the command line or as a daemon.
A window matching utility capture every windows event and can execute action based on it.
Example:
If the application firefox is open, send the application to workspace 5
With a matching utility, you can identify windows based on any x properties, for instance its title (man xprop), and act on them (or others). Example of actions are minimize, bring to front, close, make visible on all workspaces, and of course change the geometry.
Practically, you can use devilspie as follow:
1/ After working on my OPI for a few days, my windows are all scattered. My desktop is a mess. I click on a button, devilspie kicks in and reorganize all the windows in a preset configuration
2/ Today, I want to commission the injector laser. I click on a button. The injector laser environment set, the electron beam environment is hidden.
3/ This is a shared workstation where users are using the same account. User1 click on a button, his environment is restored.
wmctl: http://tomas.styblo.name/wmctrl/
devilspie: https://wiki.gnome.org/action/show/Projects/DevilsPie?action="">

Enjoy,
--
Emmanuel