We soon discovered C, and set about to create the world's most portable database. History has shown that we did indeed accomplish this. As with Java, a technical and business architecture supports Oracle portability. The technical architecture was simple. Initially there were 30 or so OSD modules.
Today there are hundreds.
OSD modules are rewritten and maintained for each platform Oracle supports. Essentially Oracle has created its own virtual machine. The Oracle portability business architecture is quite simple as well. It's estimated that for every kernel database engineer there are about three porting engineers at Oracle. Even Oracle, however, is feeling the pinch of the high cost of porting, and has started to reduce the number of supported platforms.