After some work, I'm proud to say that GIMP can now export PDF's using my new cairo-based pdf export plugin!
Go check it out - it's in the main source repository in the master branch :D
Comments and feedback are more than welcome - you have until 2.8 to affect how this plugin will work and which features it will have. Currently, it has:
- Support for multiple pages using multiple images using File->Create->Multiple-Paged PDF...
- Support for exporting text as text!!
- Support for resolutions
And it has the following optimizaiton options:
- Replace rectangles of a single color with a vector shape. This can dramatically decrease the file size (think of all the single-colored background layers that are now saved as vector instead as bitmap)
- Remove the alpha channel of layers where it's unused, to decrease the file size
- Discard layers which are not visible or are100% transparent
- Can either apply layer masks (to decrease the file size) or keep them (better quality pdf, bigger file size)
Edit: Updated the post with details on the plugin