As one of the original signatories of the Budapest Open Access Initiative, Leslie has been active in the experimentation and implementation of scholarly communication initiatives of varying scales around the world, with the goal of understanding open access for knowledge equity and inclusive development. The director of Bioline International since 2000, he was the principal investigator of the Open and Collaborative Science in Development Network (2014-2017) (OCSDNet.org), which received the SPARC Innovator Award in 2018. Leslie was also the co-chair of the 22nd International Conference on Electronic Publishing in 2018, with a focus on community based sustainable infrastructure.