Reactome (https://reactome.org) is a free, open-source, open-data, curated and peer-reviewed knowledge base of biomolecular pathways, currently covering 10,833 protein coding genes supported by 30,027 literature references. Pathways are arranged in a hierarchical structure, allowing the user to navigate from high level concepts like immune system to detailed pathway diagrams showing biomolecular events like membrane transport or phosphorylation. For the higher levels of the hierarchy, Reactome now provides scalable, interactive textbook-style diagrams in SVG format, which are also freely downloadable and editable. Repeated diagram elements like 'mitochondrion' or 'receptor' are freely available as a library of graphic elements at https://reactome.org/icon-lib. Detailed lower-level diagrams are downloadable in editable PPTX format as sets of interconnected objects, as well as in standard png format. Pathway analysis capabilities have been extended to include quantitative GSEA analysis, an R interface, and a new, visually attractive genome-wide results overview based on Voronoi maps.