v3c-dcom

v3c-dcom provides a plug-in system as an alternative COM implementation.
Unlike COM, v3c-dcom encourages the use of "sandboxes" of registered plug-ins, so allowing per site, per-group, per-user, per-program and per-job sandboxes, allowing virtually unlimited configuration and customization.
Users and client programs can even create sandboxes on the fly.

Using COM's naming scheme aims at reducing the learning curve for those familiar with COM, as does the tiny ATL implementation for C++ developers.