QuickTime X is a ground-up rebuild of the old standard (the latest prior version was 7.6) and was designed to sturdy the foundation of the platform. QuickTime X features stable new code, a new interface, screen capture functionality and allows fullscreen playback (QuickTime 7 required you to purchase the Pro version for access to this feature). However, many of the advanced features of QuickTime 7 were stripped out of QuickTime X during the rebuilding process. Lost features include:

Open Image Sequence
Clip Trimming
Clip Copy and Paste
Exporting to specific codecs
Clip resizing
and more

If you find that QuickTime X doesn’t provide the features you need, you probably need to “downgrade” to QuickTime 7. Fortunately, you can install both versions side-by-side in Snow Leopard, and even specify which files to open with either version. Unfortunately, if you try to install QuickTime 7 from the internet by downloading it, Snow Leopard will kindly tell you that you already have a newer version installed.

QuickTime 7 can be installed from the Snow Leopard disk, but almost everyone hates having to find the disk. Everyone else got it from the bittorrents.

This handy guide tells us that if we right-click on a .qtz (a Quartz Composer file) and select “Open with QuickTime,” Snow Leopard will offer us the chance to download and install QuickTime 7 automatically.

My problem is that I don’t have (or can’t find) any .qtz files on my computer! Here is where I can make your life 100% better. Ready?

Open TextEdit
Hit (shift)+(command)+T to make the document plain text
Save the document and change the file extension from .txt to .qtz

Bingo, now you have a perfectly legit .qtz file. Open it using QuickTime X and you will be prompted to install QuickTime 7.