The GIF patent is the first one that comes to mind.<p>A more recent one is Acacias patent on video transmission via networks and this gem: <a href="http://arstechnica.com/tech-policy/news/2007/04/acacia-claims-patent-on-cd-hyperlinks-sues-for-billions.ars" rel="nofollow">http://arstechnica.com/tech-policy/news/2007/04/acacia-claim...</a><p>Are there cases where software patents can be proven to have fostered innovation?