With what software can I edit/rotate mov. files?

AVS4you
is one of many free tools that allows you to do this.

Quicktime Pro does have this feature.

Open the video file & then in the top menu bar where File, View, Edit, etc, are located, click on Window. Then click on, Show Movie Properties. (or press Command, J)

In the Movie Properties window, there should be a list of 3 items. The video file name, Sound Track & Video Track.

Click on Video Track.

The bottom of the Properties window will now show the details of just the video. Which has 4 buttons, to change the orientation of the video, flip horizontally, flip vertically, rotate right, rotate left. Choose what you want & then close the window.