Making Movies in Gimp
On the subject of "How to Make Movies in GIMP" then I suggest that the current information is a little lacking.A simple tutorial can be found at http://access.lowtech.org/events/resources/gifsite/
Key tips are these:
1. Draw the background to your animation with GIMP.
2. Open the 'layers' window by clicking file/dialogs/layer,channels and paths.
3. Select "New Layer" and choose "Transparent Background".
4. Draw a "sprite" (i.e a moving character, or whatever.) on this transparent layer.
5. Don't merge the layers yet. Instead, save your working movie as an XCF file. This will preserve all the layers that you're working on. But BE WARNED - XCFs are NOT suitable for publication on the internet.
6. Note that the layer you are working on is the layer shown as BLUE in the Layers dialog. This need not be the top layer - so, yes, it is possible to mess up a layer without being able to see the damage you've done. So be careful.
7. In the Layers dialog, Duplicate your sprite layer. Now work on the new version, moving your sprite a little. You may find it easier to turn off the layer below, that contains the sprite in its previous position, by clicking the eye icon. Don't panic - that layer is still present, you just can't see it.
8. Don't forget to keep on saving. Use "Duplicate Layer" to make more and more sprite layers with your character, falling block or whatever in different positions. It's fine to keep all your previous sprite layers invisible - it'll make your picture cleaner to work with.
9. Once you're happy with the "animated movement" you've created, then duplicate the Background layer, and use the mouse to drag it up above your first sprite layer. You now want to do this over and over again, so that you have many background and sprite layers interleaved in the order sprite, background, sprite, background and so on.
10. Once you have all the layers interleaved, then save your work. Now it's time to make the animation. Right click on the top sprite layer in the Layers Dialog, and select "merge down". This pastes your sprite onto the layer directly below it, which should be a background.
11. Repeat this process until you have all your sprites merged onto the background.
12. Next up, save again, but this time choose the format .gif. You may find that it's impossible to choose "GIF" because it's greyed out. This is because you've been working in RGB mode (lost of colours) and GIFs only like Indexed Mode (256 or fewer colours). There's no need to change mode. Instead, simply choose "By Extension" as your save mode, and end the name of your with ".gif".
13. At this stage you'll get a dialog saying "Convert to Indexed?" or "Convert to Greyscale?". Unless you want your final animation in black-and-white, choose the former.
14. Now you'll get a dialog asking "Flatten" or "Save as Animation"? It's very important to click "Save as Animation" otherwise your animation will just be a picture of the top layer only, and you'll have lost the carefully merged layers you just created.
15. Smart readers will have realised that you can use this method to move two or more sprites - interleaving them sprite1, sprite2, background, sprite1, sprite2, background...
16. Okay, now you should have your animation. Open it with a web browser to see it working in all its glory. Check out a simple, but effective example of the technique described in this tutorial at:--
Thanks to James, Mozaz and Ed for the information here.