Quicktime 7.6 Mac
On the Mac side if you experience problems with this update, ie Finder crashes, reboot in Safe Boot and switch off Stuffit AVR under System Preferences, then reboot as normal.
Apple has released an upgrade to both the Mac and PC versions of its QuickTime media software, promising better performance and tighter security. QuickTime logo Regarding performance, Apple says that the upgrade to version 7.6 improves single-pass H.264 encoding quality and AAC encoding fidelity, increases the playback …
multiple macs, running 10.4.x and 10.5.x, all updated to the new QT, no problems.
Of course, it's true that I stopped using Stuffit years ago precisely because one or more Stuffit component would cause problems with system updates... <checks records> the last version I paid for was Stuffit 7, and it's up to at least 12 now. I'm still on their mailing list, though.
That's an ignorant statement because QuickTime Alternative *is* Quicktime, just with some stuff removed from the installer.
Chances are if there's a security problem in the way Quicktime renders media then it's going to affect you even if you're using QTA, and by using QTA you now have to wait longer for a 3rd party to update the hacked installer so you can update.
http://en.wikipedia.org/wiki/QuickTime_Alternative
but turning off the Stuffit AVR service (which, as far as I can remember, I've never actually used) brought everything back to normal. Apple's fault, or mine for still running 5-year-old software? The latter, I think.
A recurring strand of these regular "Apple software update breaks everything, brings Sodom and Gommorah down upon our heads" items is that the underlying cause is more often than not found to be the fault of either some buggy third-party code or some unsupported hackery on the part of the user or another piece of software: one case in particular that comes to mind is any haxie relying on Unsanity's APE.
Caveat haxxor...
@Size difference
This is most likely because the Mac includes both PPC and x86 versions of the binaries. Other possibilities are that the Mac version includes codecs which aren't licensed under Windows, or that the installer updates other system frameworks to make QuickTime work better. Also, the QTKit Cocoa libraries are only available on the Mac, but other than that functionality is generally the same on both platforms.
@Seperate from iTunes yet?
Since iTunes depends on QuickTime to work... no.