No list of software is either complete or definitive and this list does not pretend to be so. The software listed has generally been tried and found accurate and useful. Some of the software overlap in categories.
Planetarium
1 Stellarium (http://www.stellarium.org/) is a free extensive graphical package. Easy to use and useful for finding what is in the night sky from any location. It is possible to write and run scripting programmes to simualte astro events today, in the past and in the future.
Period Analysis
1 Bob Nelson (http://members.shaw.ca/bob.nelson/home.htm) provides variable star measurements for the AASVO. He has a range of free software and spreadsheets. The Minima software has been used and provides good and consistent interpolations of lightcurve minima. Also Bob gives a wide range of invaluable astronomical links http://members.shaw.ca/bob.nelson/software1.htm
2 Peranso(Period Analysis Software) is software written by Tonny Vanmunster who undertakes precision CCD variable star measurement. This software provides a wide range of tools for all aspects of period analysis. A single licence is €30. http://www.peranso.com/
3 Period04 Period analysis software written by astronomers at the University of Vienna. Has not been tried but is free with an extensive manual. Visit http://www.univie.ac.at/tops/Period04/
Photometry
1 MaxIm DL (http://www.cyanogen.com/) provides and extensive suite of software for photometry as well as telescope and DSLR software. Widely used it is priced at about $665.
2 AIP4WIN (Astronomical Image Processing for Windows) is a software package for photometery that comes with an extensive hardback manual and the package is priced at $100. Visit http://www.willbell.com/aip/index.htm
Simulation
1 Binary Maker 3 (http://www.binarymaker.com/) accurately calculates light and radial velocity curves for almost any type of binary, simultaneously displaying the theoretical and observed curves as well as a 3-D model of the orbiting stars. Written by Professor David Bradstreet at Eastern University, Pennsylvania and costs $100
2 PHOEBE (Physics Of Eclipsing Binaries): scientific code for full-fledged modeling and analysis of eclipsing binary stars, build on basis of the Wilson-Divenny code. Written by astronomers at the Universities of Ljubljana, Leuven and Central Lancaster this software package is free. Visit http://phoebe.fmf.uni-lj.si/
Data Reduction
1 Astrometrica. Astrometrica is a interactive software tool for scientific grade astrometric data reduction of CCD images. The package costs €25. Visit http://www.astrometrica.at/
2 MPO Canopus is a full-featured astrometry and photometry program capable of providing high accuracy results in both fields. At a cost of $65 more information at http://www.minorplanetobserver.com/MPOSoftware/MPOCanopus.htm
3 GAIA (http://star-www.dur.ac.uk/~pdraper/gaia/gaia.html LINUX and Mac OS) is an highly interactive image display tool but with the additional capability of being extendable to integrate other programs and to manipulate and display data-cubes. At present image analysis extensions are provided that cover the astronomically interesting areas of aperture & optimal photometry, automatic source detection, surface photometry, contouring, arbitrary region analysis, celestial coordinate readout, calibration and modification, grid overlays, blink comparison, image defect patching, polarization vector plotting and the ability to connect to resources available in Virtual Observatory catalogues and image archives, as well as the older Skycat formats. A Windows version can be found at... http://astro.dur.ac.uk/~pdraper/cygwin/