To convert Apple Quicktime .MOV files to AVI files (which almost all encoder/decoders/video editing tools can read):
Use the free "Bink and Smacker" RAD Video tools
http://www.radgametools.com/
it can do just that...
A tut on this can be found here:
http://www.videohelp.com/mov2avi.htm
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Also the little tool called
mov2avi can do it for free (but doesn't provide much configuration)
http://www.divx-digest.com/software/mov2avi.html
and a GUI for it is found here:
http://www.videohelp.com/tools?tool=274
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Remember that your file will still be very huge!! Changing the fileformat often doesn't change a thing in filesize (well not much anyways). You need to recode it at a lower bitrate and/or decreasing the screensize and/or decreasing the FPS and/or etc. etc...
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How to find all this? Just use google: "mov2avi"