The CENDARI SUSTAIN Working Group has been convened as an element of the CENDARI project sustainability plan. CENDARI was a funded advanced community research infrastructure project, with an active development period of 2012-2016. In order to ensure that the user communities and tools that have been built during the lifetime of the project continue to have a context for their maintenance and development, a core of the CENDARI leaders will contribute to the WG over the course of three years, with the intention of seeking further funding for active development at the end of that period.