MuST stands for Multipurpose Survey Tool is a web service specially designed for acquiring and storing data from surveys using questionnaires, or data acquired from sensor networks. MuST supports various protocols and can accept various data sources, but is tailored for working together with MUCHACHA, the Medical Utility Calculator platform for Health Application. Together, these tools can be used for both online and offline surveys in synchronous or asynchronous mode. The resulting functionality is a very versatile tool specifically designed for medical inquiries, but suitable for generic applications as well.

MuST implements surveys in a very flexible manner, allowing for the definition of non-linear questionnaires (where questions may depend on answers previously given to former questions) through a sophisticated stand-alone editor. The questionnaires are implemented in XML files that may be downloaded on the MuST server, and later on distributed on selected, authentified mobile devices (smartphones and/or tablets) where the questions may be answered by users taking part to the survey. Different roles may be assigned to the participants of the survey (survey editor, validator, investigator or end-user of the acquired data). An administrator manages the system.