With MoinMoin you can directly append files to a wiki page.
Input
[[attachment:letter.txt]] {{attachment:foto.jpg}}
Display
As long as the files aren't uploaded:
- the links are grey (like links to non-existent wiki pages).
- an alternate image, like a paper clip, is displayed for non-existent embedded pictures.
You can click on it and upload the file from your computer's file system to the wiki using your browser. Then the design is regular and:
- links are blue.
- the image appears.