Maelstrom (www.maelstrom-research.org) is the main international tool for cohort management, currently holding a structured metadata catalogue of circa 280 cohorts worldwide.
This system provides purpose-built tools for cataloguing and presentation of cohorts; for initiation, examination and extension of cohorts; for investigating potential for collaboration and sample size estimations; for harmonisation of variables; and for federated statistical analysis. Maelstrom Research has developed the OBiBa open-source application suite, encompassing a number of software solutions designed specifically for epidemiology, utilized by Cohorts.se.