So, are all of these suites, as Heavy Equipment, for example, products for Object Desktop, let's say? Something as "add-ons"?
Heavy Equipment was a Community project several years ago which was a group effort to skin [using matching base graphics] pretty well every 'skinnable' grogram/application that was available at the time. From memory more than 20 skinners provided works for more than 50 separate programs.
Many of the more popular/famous Windowblinds skins have been adapted to other programs...in other words contributors have skinned other apps using [with consent] the original graphics and/or style of the original source.
For example... I still use daily my 'Antares' Sysmetrix skin which was created from treetog's 'Antares' Windowblind.
Of course, by the time you mix and match the sky's the limit for a desktop's 'originality' ....