World Day Against Software Patents is observed worldwide every September 24. Established by the Foundation for a Free Information Infrastructure (FFII) in 2008, this day commemorates the anniversary of the initial adoption of a controversial EU directive regarding the patentability of computer-implemented inventions. The FFII, a non-profit organization founded in Germany in 1999, aims to promote a free market in information technology by opposing software patents, which are often criticized for stifling innovation and leading to competing, incompatible software formats. On this day, supporters advocate for the cessation of software patents, highlighting the negative impact these patents can have on free and open-source software projects. The observance serves as a platform for discussions on the implications of software patents and the ongoing debate about their validity and extent.