# IRAF Command Language ## Identification [[Image Reduction and Analysis Facility|IRAF]] is an astronomical data-reduction environment; `cl` is its Command Language shell. `login.cl` is a user startup file; `logout`/`bye`/`quit` have shell/package semantics. [[National Optical Astronomy Observatory|NOAO]] developed IRAF for optical astronomy. SODAR, ISAAS, and JAXA are separate atmospheric/institutional possibilities whose exact relationship to the installation is unresolved. ## Notebook evidence - [[Scanned_20260730-1659#PDF page 58 — IRAF shell, installation, and NOAO optical-astronomy package|PDF page 58: IRAF shell, installation, and NOAO optical-astronomy package]] — IRAF—the Image Reduction and Analysis Facility—is a general astronomical data-reduction system developed by NOAO; the community distribution continues after NOAO ended institutional maintenance. The page captures its CL shell semantics, `login.cl`, package exit/logout commands, and its broad optical-astronomy tool ecology. The handwritten “IRAF64” and 2019 dates likely record an installation attempt on a 64-bit environment. ## Relationships and overlays The source places this record in an evidence cluster with [[Image Reduction and Analysis Facility|Image Reduction and Analysis Facility]] · [[Japan Aerospace Exploration Agency|Japan Aerospace Exploration Agency]] · [[National Optical Astronomy Observatory|National Optical Astronomy Observatory]] · [[Optical Astronomy|Optical Astronomy]] · [[SODAR|SODAR]]. The occurrence contributes to the notebook's larger model of [[Identity Continuity|identity continuity]], [[Device Sovereignty|device sovereignty]], and [[Continuity Architecture|continuity architecture]]. ## Evidentiary status and open leads Recover machine/OS and installation logs for the 2019 IRAF setup; resolve C-SODAR/ISAAS/JAXA. ## Source - [[Scanned_20260730-1659|Scanned_20260730-1659]]