AIPS - Astronomical Image Processing System
[open source - Unix, and VMS] A software package for interactive (and, optionally, batch) calibration and editing of radio interferometric data and for the calibration, construction, display and analysis of astronomical images made from those data using Fourier synthesis methods.
http://www.cv.nrao.edu/aips/

IRAF - Image Reduction and Analysis Facility
[open source - Unix, OpenVMS] A general-purpose software system for the reduction and analysis of astronomical data. IRAF is written and supported by the IRAF programming group at the National Optical Astronomy Observatories (NOAO) in Tucson, Arizona.
http://iraf.noao.edu/

ESO-MIDAS: Image Data Analysis System
[open source - Linux/Unix, VAX/VMS/OpenVMS] General tools for image processing and data reduction with emphasis on astronomical applications including stellar and surface photometry, image sharpening and decomposition, as well as imaging and special reduction packages for ESO instrumentation.
http://www.eso.org/esomidas/

AIPS++
[open source - Unix, WinNT] The next generation AIPS software.
http://aips2.nrao.edu/docs/html/aips++.html

GIPSY - Groningen Image Processing System
[open source - Unix] A highly interactive software system for the reduction and display of astronomical data.
http://www.astro.rug.nl/~gipsy/

SuperFix/MegaFix
[commercial - DOS, Win3.1] CCD image processing software for amateur astronomers. Handles most file and camera formats. Allows tricolor imaging and 'track-and-stack as well'.
http://members.aol.com/bjohns7764/

IDL - Interactive Data Language
[commercial - multiplatform] Data analysis, visualization, and cross-platform application development software.
http://www.rsinc.com/idl/

PV-WAVE
[commercial - multiplatform] Advanced visual data analysis software.
http://www.vni.com/products/wave/

MaxIm DL
[commercial, demo available - Win95/98/NT/2000] Image processing and CCD camera control software for astronomical imaging. Supports Apogee, Celestron, FLI, HiSIS, Meade, SBIG, and Starlight Xpress CCD cameras; video cameras, autoguiders, and filter wheels. ASCOM compliant.
http://www.cyanogen.com

Seeing simulation and deconvolution
GPL implementation of a seeing simulator and deconvolution via Cross-spectrum and Bi-spectrum.
http://www.infis.univ.ts.it/~chri/seeing/index.html

MIRA
[commercial - Win95/98/NT] Scientific image processing and analysis software.
http://www.axres.com/

AstroArt
[commercial, demo available - Win95/98/NT] A complete software product for analysis and processing of astronomical images. With the built-in star atlas based on the Guide Star Catalogue, it is also possible to perform astrometric and photometric calibration on your images.
http://www.sira.it/msb/astroart.htm

CCDSoFT
[commercial, demo available - Win95/98] Main image processing features: unsharp mask, maximum entropy and Lucy-Richardson deconvolution, multilayer with auto-align, median, mosaic, RGB, LRGB images.
http://www.ccdsoft.com/

Quantum Image
[commercial - Win95/98/NT] Image restoration program, it can restore and enhance defect images (ex. out of focus and noise).
http://www.quantimage.com

Auriga Imaging
Auriga Imaging's program RegiStar automatically registers (aligns) astrophotos -- no user intervention required.
http://www.aurigaimaging.com

CCD Astronomy
[some are free, MS-Win] Software tools for Cookbook camera.
http://home.t-online.de/home/mrimkus/astrmain.htm

AIPS++
Software system for astronomical data reduction on parallel computers. Provides the capability for calibration, editing, image formation and enhancement, analysis of images and other data streams.
http://monet.astro.uiuc.edu/aips++/

MIIPS
[open source - OpenVMS/Unix] Multipurpose Interactive Image Processing System does astronomical image analysis. The main package runs on OpenVMS, but many subsets can run on Unix. All source code is provided.
http://www.chara.gsu.edu/~gudehus/miips.html

ISDA - Irregularly Spaced Data Analysis
[Free - MSDOS, dosemu] Program to analyse irregularly spaced time series - variable star light curves.
http://jupiter.aai.ee/~pelt/soft.htm

MIRIAD - Multichannel Image Reconstruction, Image Analysis and Display
[open source - Unix, VMS] A toolbox in the form of an environment with a large set of moderate-sized programs which perform individual tasks involving calibration, mapping, deconvolution and image analysis of interferometric data.
http://bima.astro.umd.edu/miriad/

Pleinpot
[open source - Linux/Unix] Astronomical software for data reduction and analysis. This is the software used by the Hypercat database.
http://www-obs.univ-lyon1.fr/hypercat/install/mirror.html

Registax
Registax is a freeware tool that registers, stacks and processes image sequences. The program accepts either BMP's or AVI-files as input and will save the results as BMP or FITS.
http://aberrator.astronomy.net/registax

Picture Window Image Editing Software
Color.
http://www.dl-c.com

Voyager Image Display
A shareware Windows 95/98/NT/2000 based image processing program that can read and enhance images from various NASA spacecraft.
http://members.optusnet.com.au/serpentis