Unipept (http://unipept.ugent.be) is a web application that offers a 
user-friendly way to explore the biodiversity of complex metaproteome samples by 
providing interactive visualizations. In this article, the updates and changes 
to Unipept since its initial release are presented. This includes the addition 
of interactive sunburst and treeview visualizations to the multipeptide 
analysis, the foundations of an application programming interface (API) and a 
command line interface, updated data sources, and the open-sourcing of the 
entire application under the MIT license.