REVIGO is a web server that summarizes and visualizes long lists of Gene Ontology (GO) terms. It reduces redundancy by clustering similar terms and provides multiple visualization methods, including multidimensional scaling, graphs, treemaps, and tag clouds. The server uses semantic similarity measures to identify representative terms and allows users to adjust the threshold for redundancy reduction. REVIGO is freely available at http://revigo.irb.hr/. It complements existing tools like GOrilla and RedundancyMiner by offering a more efficient way to interpret GO term lists. REVIGO supports various visualization techniques to help users explore the data, including scatterplots, interactive graphs, treemaps, and tag clouds. It also provides 'dispensability' and 'uniqueness' values to assess the significance of terms. REVIGO is designed for researchers dealing with high-throughput data, offering a user-friendly interface without requiring software installation or complex input formats. It is particularly useful for quickly analyzing GO term lists and visualizing results. The tool is based on semantic similarity measures and is compatible with various data sources. REVIGO is compared with other tools like RedundancyMiner, highlighting its advantages in terms of implementation, interoperability, and visualization options. The server is freely available and can be accessed through any modern web browser with Adobe Flash capabilities. It is an essential tool for researchers in the life sciences who need to interpret GO term lists from high-throughput experiments.REVIGO is a web server that summarizes and visualizes long lists of Gene Ontology (GO) terms. It reduces redundancy by clustering similar terms and provides multiple visualization methods, including multidimensional scaling, graphs, treemaps, and tag clouds. The server uses semantic similarity measures to identify representative terms and allows users to adjust the threshold for redundancy reduction. REVIGO is freely available at http://revigo.irb.hr/. It complements existing tools like GOrilla and RedundancyMiner by offering a more efficient way to interpret GO term lists. REVIGO supports various visualization techniques to help users explore the data, including scatterplots, interactive graphs, treemaps, and tag clouds. It also provides 'dispensability' and 'uniqueness' values to assess the significance of terms. REVIGO is designed for researchers dealing with high-throughput data, offering a user-friendly interface without requiring software installation or complex input formats. It is particularly useful for quickly analyzing GO term lists and visualizing results. The tool is based on semantic similarity measures and is compatible with various data sources. REVIGO is compared with other tools like RedundancyMiner, highlighting its advantages in terms of implementation, interoperability, and visualization options. The server is freely available and can be accessed through any modern web browser with Adobe Flash capabilities. It is an essential tool for researchers in the life sciences who need to interpret GO term lists from high-throughput experiments.