Under German copyright law, rights of use cannot be granted for so-called unknown types of use. Software-as-a-Service (hereinafter: “SaaSâ€) is a use considered to be unknown until the mid 1990s. When taking the law in a literal sense, Free and Open Source Software (hereinafter: “FOSSâ€) licenses granted before then thus cannot grant the rights of use necessary for SaaS, meaning that some FOSS cannot be lawfully made available via SaaS under German copyright law.