@istewart I had more the previous Apple projects in mind, like Copland, OpenDoc, QuickDraw GX (although TrueType GX became OpenType variable fonts), way before OS X.

@istewart @sansruse there was also the software crisis, where Microsoft and Apple even more so struggled to move to the new shiny OS because of all the legacy hacks in the apps. The web browser is a monster of complexity compared to these operating systems.