Comment by immibis

It's not so much "before its time" as already had its time cut short, but Microsoft OLE. The premise was that you could insert any document into any other document. Worked with Office programs, mspaint, and some third-party programs. For example at school we had an electricity simulation program called Crocodile Physics, and you could embed a simulation in a PowerPoint slide.

And the similarly named but completely separate OLE Automation, which let you script programs, across process boundaries. This is what let you write in VB(A): Set w = New Word.Application: Set e = new Excel.Application: Set doc = w.Open("foo.doc"); etc... - this was to Office (mostly) what shell scripting is to Linux, and enabled a lot of ad-hoc business process automation.