Spilhaus, as it flows downstream from PROJ

+proj=spilhaus arrived in PROJ 9.6.0 (March 2025). Which of your tools can use it depends on which PROJ each one carries. These pages draw the same map in several runtimes and, more to the point, print the table of who has what.

The pages

• Python notebook - pip environment; pyproj, rasterio, pyogrio and the GDAL bindings each with their own PROJ. Bathymetry over /vsicurl, Natural Earth, landmarks, the WKT question, and a second member of the family.
• R version - gdalraster, wk and ximage, rendered on two Ubuntu runners that differ only in the system GDAL/PROJ: stock apt and ubuntugis-unstable.
• Browser version - the vector half, run by pyproj inside Pyodide. One more PROJ to ask.

Companion blog post

• The road to +proj=spilhaus

Run it yourself

• uvx marimo edit --sandbox spilhaus.py (source)
• quarto render spilhaus.qmd (source)
• spilhaus_wasm.py for the browser build