The Mollom [v0.3.1] & SpamPotection [v0.4.1] downloads from http://www.silverstripe.org/modules/ contain folders but no files.
http://www.silverstripe.org/mollom-module/ links to http://www.silverstripe.org/assets/Uploads/mollom-v0.3.1.zip
http://www.silverstripe.org/spam-protection-module/ links to http://www.silverstripe.org/assets/Uploads/spamprotection-v0.4.1.zip
Both also link to github where the working downloads are available...
https://github.com/silverstripe/silverstripe-mollom
https://github.com/silverstripe/silverstripe-spamprotection
...but it is confusing & annoying to have downloads that don't work.