Multitasking, SOM (contrary to COM, it does implementation inheratance across languages, multiple inheritance and has meta-classes), object based desktop, Smalltalk for business application development (basically a similar role as VB and .NET have gotten latter on on Windows), Visual Age for C++ had a Smalltalk like experience (although ported to Windows as well).

However this also meant a more beefy hardware than the DOS/Windows 3.x combo.