Install wcslib with Homebrew, apk, apt, dnf, MacPorts, Nix, pacman, zypper

Project links

• Homepage
• Upstream docs
• Package manager page

Commands and aliases

• HPXcvt
• fitshdr
• sundazel
• tofits
• wcsware

Project history

The WCSLIB manual identifies it as an implementation of the FITS WCS standard and carries copyright dates beginning in 1995. The surrounding FITSWCS site ties the library to the formal WCS papers by Greisen, Calabretta, and collaborators that standardized how FITS headers describe pixel-to-world transformations.

The FITSWCS literature page records the first two core WCS papers in Astronomy & Astrophysics in 2002: Paper I on world coordinates in FITS and Paper II on celestial coordinates. Later papers extended the standard to spectral coordinates in 2006, HEALPix/HPX in 2007, the XPH butterfly projection in 2013, and time coordinates in 2015.

WCSLIB grew alongside those standards as a reference-quality implementation for projection math, coordinate transformations, test data, Fortran bindings, and utilities. The upstream site notes that, as of release 8.5, RCS version files are included in the distribution to document changes since v1.0.

Adoption history

WCSLIB adoption is strongest in astronomy software stacks that read, validate, transform, or display FITS WCS headers. NASA's FITS WCS page lists WCSLIB among the software libraries available for the WCS conventions, and Astropy's `astropy.wcs` documentation says its low-level core WCS support is based on Mark Calabretta's wcslib.

The batch package metadata shows WCSLIB packaged across Homebrew, Alpine, Debian/Ubuntu, Fedora, MacPorts, Nix, Arch, and openSUSE. That broad distro presence reflects its role as a shared scientific dependency rather than an end-user application.

How it is used

Developers use WCSLIB from C or Fortran to parse FITS headers, initialize WCS data structures, and convert between pixel coordinates and celestial, spectral, time, or other world coordinates. Command-line utilities such as `fitshdr`, `wcsware`, `HPXcvt`, `sundazel`, and `tofits` expose parts of that functionality for inspection, conversion, and testing.

In the wider Python ecosystem, many users meet WCSLIB indirectly through Astropy, where FITS WCS transformations are presented through high-level and low-level APIs. The same underlying package matters to observatory pipelines, map projection tools, FITS validators, and visualization programs that need consistent coordinate behavior.

Why package nerds care

WCSLIB is package-nerd significant because it packages a domain standard's math, edge cases, and historical compatibility into a reusable native library. Scientific package managers care about it for the same reason they care about CFITSIO: a small C library becomes the coordination point between decades of file-format convention and modern language bindings.

Its utilities also make it useful outside library linking. A maintainer debugging a FITS header can install the package and inspect WCS interpretation from the shell, which is often faster than writing a short scientific Python script just to discover whether a header is malformed.

Timeline

• 1995: WCSLIB copyright history begins in the upstream manual.
• 2002: FITS WCS Papers I and II are published in Astronomy & Astrophysics.
• 2006: Paper III on spectral coordinates is published.
• 2007: HEALPix/HPX projection paper is published.
• 2013: XPH butterfly projection paper is published.
• 2015: FITS time coordinate paper is published.
• 2025: Upstream site notes WCSLIB 8.5 and inclusion of RCS version files documenting changes since v1.0.

Related projects

• Related projects include FITS, CFITSIO, Astropy `astropy.wcs`, WCSTools, Starlink AST, PGPLOT/PGSBOX, HEALPix, NASA HEASARC FITS resources, and the IAU FITS Working Group standards process.

Sources

• https://docs.astropy.org/en/latest/wcs/index.html
• https://fits.gsfc.nasa.gov/fits_wcs.html
• https://www.atnf.csiro.au/computing/software/wcs/
• https://www.atnf.csiro.au/computing/software/wcs/wcslib/index.html
• input source_facts.package-manager