OpenBudgets.eu (OBEU) provides an open-source software framework and accompanying Software-As-A-Service (SAAS) platform for supporting financial transparency, thus enhancing accountability within public sectors as well as influencing corruption prevention. To this end, a scalable framework for multi-stakeholders is developed, with the aim of maximizing flexibility and ease of use. The core features of the OBEU platform are: (1) A semantic data model used to integrate heterogenous budget data, giving a pre-defined structure to the input data; (2) a library of visualisation tools with a user-friendly interface, which enables stakeholders to visualise available data in different granularity and modality; (3) a library of data mining and comparative analysis tools, which enables the aggregation of existing data in order to obtain new outcomes and discover recent trends and patterns, and potentially forecasting budget measures; and (4) an interface for feedback and citizen engagement which enables users to evaluate, discuss and give feedback on the provided data. A demonstration of the OBEU platform and portal is available at http://apps.openbudgets.eu/ and can be easily embedded into municipalities’ websites.