An overview of the commercialisation of open source and a review of the potential revenue models and their interface with open source, from the first study into this in 2008 to the recent shift by Elastic away from open source to the SSPL licence. Amanda is the editor of Open Source, Law, Policy and Practise with over 20 authors, to be published in September and as the author of the chapter on commercial models and open has spent some time researching this area. She has spent over 13 years working in and around open source software and its commercialisation.