For more direct evidence in the form of specific examples there's an old HN thread from 2010 about this: "Ask HN: Cases where software patents have prevented pr

For more direct evidence in the form of specific examples there's an old HN thread from 2010 about this: "Ask HN: Cases where software patents have prevented progress?" [0] Some examples include arithmetic coding[1], elliptic curve cryptography[2], and LZW/GIF[3]. Apple dropped ZFS because of licencing concerns[4] (dooming us all to listen to John Siracusa complain about HFS+ and lamenting the absence of ZFS for the last 6 years). Many of these have since expired and have had a burst of activity around them afterwards. [0]: https://news.ycombinator.com/item?id=1075505 https://news.ycombinator.com/item?id=1075505 [1]: https://en.wikipedia.org/wiki/Arithmetic_coding#US_patents https://en.wikipedia.org/wiki/Arithmetic_coding#US_patents [2]: https://en.wikipedia.org/wiki/ECC_patents https://en.wikipedia.org/wiki/ECC_patents [3]: https://en.wikipedia.org/wiki/GIF#Unisys_and_LZW_patent_enforcement https://en.wikipedia.org/wiki/GIF#Unisys_and_LZW_patent_enfo... [4]: http://arstechnica.com/apple/2009/10/apple-abandons-zfs-on-mac-os-x-project-over-licensing-issues/ http://arstechnica.com/apple/2009/10/apple-abandons-zfs-on-m...