Decidim is a free software digital platform that supports citizen participation and democratic governance in institutions and organisations. It enables the creation of spaces for submitting proposals, deliberating, making collective decisions and monitoring commitments, for example in participatory budgeting processes. Its flexibility allows it to be adapted both to processes open to the public and to organisations’ internal participation. The platform incorporates transparency and traceability principles and is developed with the participation of an open community that also takes part in its governance. Researchers from UOC’s CNSC group are also involved in creating this collective initiative, contributing research on citizen participation and digital democracy.