As part of its patent pool, Luxembourg-based Sisvel is selling a patent license for AV1 video, the basis for AVIF. This pool of inventions was announced in early 2019, but claims appeared on 10 March 2020. It comprises more than a thousand patents. The claims are subject to challenge. Sisvel has stated that it will not seek royalties for content; however, its license does not exempt software. AOM has not responded to the patent claims. In response to the initial announcement from Sisvel, AOM reiterated its commitment to royalty-free patent licensing and mentioned a patent defense program to help protect AV1 ecosystem participants from unfair patent infringement claims.