QLFits

The plugin integrates with macOS Quick Look to render FITS (Flexible Image Transport System) files directly in the Finder. When a FITS file is selected and the space bar pressed, it displays HDU headers and, when possible, visualizes 2‑D images and 1‑D spectra, supporting a wide range of extensions such as *.fits*, *.fit*, *.fts*, *.uvfits*, *.pha*, *.rmf*, *.arf*, *.rsp*, *.pi*, *.lc*, *.evt*, *.att*, and *.orb*.

It is built on the open‑source ObjCFITSIO and AstroCocoaKit libraries and works on macOS 10.8 and later. The Quick Look generator can be installed via Homebrew or by placing the bundle in the system or user QuickLook directory, followed by a quick `qlmanage -r` to refresh the daemon.

The project is released under the GNU General Public License, and developers can contribute by modifying the Objective‑C code, rebuilding with Carthage‑managed dependencies, and submitting pull requests. A companion Spotlight plugin, FITSImporter, is also available.