Donald Trump's fledgling social media site, Truth Social, has been accused of using open-source software while failing to comply with the terms of the licence under which that software is issued. The allegation is that Truth Social is based on the code of Mastodon, a free and open-source software platform for building social media websites. Importantly, Mastodon is released under the AGPLv3, which includes a 'copyleft' clause that requires that a user of the code to make available the entire 'Corresponding Source' that is based on that code. The Software Freedom Conservancy has given the Trump Media and Technology Group with 30 days to comply with the AGPLv3 licence (i.e. to make the code available to those that requested it) or the Group's licence to use the code will be terminated.
Not all open source licences have copyleft provisions, and some are more compatible than others with particular commercial strategies, such as patenting. Companies must be vigilant when using open-source code in commercial and proprietary systems to ensure that the licence in question is suitable for their commercial purposes. It is crucial that anyone intending to rely on open source licence provisions or thinking of patenting software-based inventions seek professional advice from the outset.