CBRAIN is a web-enabled grid platform that facilitates collaborative research on large, distributed data by creating an interface between a user (or a group of collaborating users) and high-performance computing centres (HPCs). Behind the web-portal, CBRAIN manages data access, transfer, caching and provenance, as well as data processing and reporting. CBRAIN is generic and modular, it can easily be extended with new data models and tools for a broad range of research disciplines.