Circos is a visualization tool designed to facilitate the identification and analysis of similarities and differences in genome comparisons. It uses a circular ideogram layout to display relationships between pairs of positions using ribbons that encode position, size, and orientation of genomic elements. Circos can display data as scatter, line, histogram plots, heat maps, tiles, connectors, and text. It can generate barmaps or vector images from GFF-style data inputs and hierarchical configuration files, which can be easily generated by automated tools, making it suitable for rapid deployment in data analysis and reporting pipelines. The tool is effective in displaying variation in genome structure and any other positional relationships between genomic intervals. It is particularly useful in comparative genomics, where the field has transitioned from comparing reference sequence assemblies to comparing individual genomes. Circos addresses the challenge of visualizing large volumes of genomic rearrangement data by applying the circular ideogram layout, which is effective for illustrating local alignments between similar sequences. Circos has been used to visualize genomic data, including end-sequence profiling and fingerprint profiling of cancer genomes. It is a mature software package that has been used in various applications, including whole-genome analysis of genomic rearrangements in follicular lymphoma. The tool allows for the visualization of structural changes in tumor genomes, identification of BACs spanning rearrangement breakpoints, and the analysis of sequence contigs containing breakpoints. Circos provides a flexible and scalable means to illustrate relationships between genomic positions and allows for the flexible rearrangement of elements in the image. It can be used to visualize data from various domains, including genomics, and has been used to generate images for book and magazine covers, as well as to provide scientific context to a David Cronenberg cinema artbook. The tool is capable of adjusting the global magnification for each ideogram and smoothly varying the magnification within a region, which is effective for emphasizing fine structure of data in a region while preserving context. Circos also allows for the use of run-time rules to control the visibility and format of data elements based on their position, value, or format characteristics. This enables the creation of diverse visualizations in various data domains and facilitates batch generation of images. Circos has been used to visualize data from the field of genomics, generate images for book and magazine covers, and even to provide scientific context to a David Cronenberg cinema artbook. It is a powerful tool for visualizing genomic data and has been widely adopted due to its clarity, high data-to-ink ratio, and favorable scaling characteristics.Circos is a visualization tool designed to facilitate the identification and analysis of similarities and differences in genome comparisons. It uses a circular ideogram layout to display relationships between pairs of positions using ribbons that encode position, size, and orientation of genomic elements. Circos can display data as scatter, line, histogram plots, heat maps, tiles, connectors, and text. It can generate barmaps or vector images from GFF-style data inputs and hierarchical configuration files, which can be easily generated by automated tools, making it suitable for rapid deployment in data analysis and reporting pipelines. The tool is effective in displaying variation in genome structure and any other positional relationships between genomic intervals. It is particularly useful in comparative genomics, where the field has transitioned from comparing reference sequence assemblies to comparing individual genomes. Circos addresses the challenge of visualizing large volumes of genomic rearrangement data by applying the circular ideogram layout, which is effective for illustrating local alignments between similar sequences. Circos has been used to visualize genomic data, including end-sequence profiling and fingerprint profiling of cancer genomes. It is a mature software package that has been used in various applications, including whole-genome analysis of genomic rearrangements in follicular lymphoma. The tool allows for the visualization of structural changes in tumor genomes, identification of BACs spanning rearrangement breakpoints, and the analysis of sequence contigs containing breakpoints. Circos provides a flexible and scalable means to illustrate relationships between genomic positions and allows for the flexible rearrangement of elements in the image. It can be used to visualize data from various domains, including genomics, and has been used to generate images for book and magazine covers, as well as to provide scientific context to a David Cronenberg cinema artbook. The tool is capable of adjusting the global magnification for each ideogram and smoothly varying the magnification within a region, which is effective for emphasizing fine structure of data in a region while preserving context. Circos also allows for the use of run-time rules to control the visibility and format of data elements based on their position, value, or format characteristics. This enables the creation of diverse visualizations in various data domains and facilitates batch generation of images. Circos has been used to visualize data from the field of genomics, generate images for book and magazine covers, and even to provide scientific context to a David Cronenberg cinema artbook. It is a powerful tool for visualizing genomic data and has been widely adopted due to its clarity, high data-to-ink ratio, and favorable scaling characteristics.