I don’t know whether these are compelling upgrades – haven’t tried them, don’t know about new features – but Adobe has released Acrobat Reader 5.0 and Apple finished work on Quicktime for Windows 5.0. Acrobat 4.0 was very polished and stable, and I’m not sure what would make a new version seem like a big improvement. Quicktime, on the other hand, has long been one of my least favorite programs, persistently buggy and annoying. It would be nice to think that the new version changes all that, but I’m not holding my breath.
