Gnome used CORBA in the form of Bonobo and KDE reinvented the wheel with DCOP.
And, yeah, if memory serves CORBA worked well enough for Gnome but not KDE because the C++ story was not great. Whatever bindings being used were dependent on features not well supported by G++, templates being painfully slow to compile, etc.
kde in it's turn were heavily reliant on it (mico) for embedding and communication. but compilation was indeed painfully slow (i still remember never ending kde compiles in 99-2000) so they came up with dcop/kparts after having few drinks and deciding that they can do better
In the end, both teams decided that assuming components running in remote processes was the wrong default. I'm not sure what GNOME replaced them with, but KParts rescued KDE 2.0
in gnome i think they did something like "gparts" based on glib. but because gnome desktop was composed in large part from applications written in gtk and not in gnome libs it never had too much uptake (unlike in kde). but i might be wrong - i been kde user from 1.0 alpha4 and gnome was parallel universe
https://www.linuxjournal.com/magazine/kdemdashthe-next-gener...