There are several different flavors of shavette out there.

A stock Dovo uses half a DE blade, but also has holders which will accept longer then usualy DE looking blades as well as rigid back blades.

Fromm uses rigid back blades from the word go.

Then there's the Feather, which has its own blades. Some of the guys at SMF are taking feather blades, cutting them down and using them in the old injector razors.