Why device drivers in user space; different possibilities for getting device drivers; DDE's origins and rationale.
Structural overview of the components.
DDE essentially is a glue layer to embed Linux device drivers into another environement. In the DDE case, this other environment is a user-space task -- compared to the GNU Mach kernel having a in-kernel Linux 2.0 device drivers glue code (cf. paper by Goel et al.).