Ion is a tiling (no overlapping windows) window manager that also has PWM-style tabbed frames which can contain multiple client windows. These features help to keep windows organized and to switch quickly between them. Ion was designed primarily as an efficient and unobtrusive window manager for users who prefer the keyboard.
Riot is a tool for keeping (textual) information organised. It is a todo list and note manager, and a manager for whatever information one might collect. It has an interface resembling those of slrn and mutt and all text editing is done with an external editor, making it a nice browser for collections of text.
Re: Great Start
> It's a shame that PWM's development was
No, it was not abandoned. There hasn't been any new relases in quite a long time but lately there's been some work done on a new version. Have a look at the PWM web page for details.
> PLEASE, resume the development of PWM !!
The development of PWM has not been abandoned, only the two window managers are in the progress of being unified. PWM will eventually be implemented on top of 'ioncore' by loading floatws and menu modules.