The COVID moonshot project for example, yielded new potential inhibitors with a collaborative, crowdsourcing Open Science Discovery approach , now continued within the Drugs For Neglected Diseases Initiative. Here we present the results of our crowd-sourced community initiative, the "Billion molecules against Covid-19 Challenge", which was organized as a competition (starting May 2020) to identify inhibitors of SARS-CoV-2 proteins. Participating teams screened at least one billion molecules each using diverse computational methods. Then, the most promising drug compounds were synthesized and evaluated in wet-lab experiments. We present the discovered small molecule inhibitors and lessons learned from the challenge.