TOPCAT is a desktop GUI tool for working with tabular data such as source catalogues. Among other capabilities it provides a rich set of visualisation options suitable for interactive exploration of large (many rows) and high-dimensional (many columns) datasets.

The latest release introduces a Corner Plot window which displays a grid of linked scatter-plot-like and histogram-like plots for all pair and single combinations from a supplied list of coordinates. This type of visualisation is not novel; it has been used since the 1980s under the names "Scatter Plot Matrix", "SPLOM", "Pairs Plot" and "Corner Plot" and can be generated for instance in Python, R and IDL. But its inclusion in TOPCAT benefits from the interactivity, performance, scalability, flexibility, and ease of use provided by the existing GUI, and gives TOPCAT users a new tool for exploration of high-dimensional data.