Gantrithor is a data annotation tool that enables rapid, bulk data annotation over datasets. It allows the annotator to annotate thousands of labels in a single second, by grouping similar data into locus's on a scatter plot. All of this can be done while simultaneously training, predicting, or evaluating a model. Gantrithor has a free version, which limits datasets to 1000 documents, and a Professional version, which has no limit on the size of a dataset.