We describe ORBiT, the Oak Ridge Biosurveillance Toolkit, the objective of which is to provide 1) forecasting and early warning, and 2) an extensible data analytics platform for biosurveillance by enabling the use of traditional and non-traditional datasets, consisting of heterogeneous data types and modalities. ORBiT includes a data collection interface, analytic components, higher-order statistical tools, and a visual front-end with visual analytics. ORBiT is implemented as a distributed analytic platform consisting of a software stack atop of Hadoop and uses Titan, a distributed graph database as a backend for data storage.