yaxx
Yaxx is an Open source tool to facilitate automated processing and analysis of X-ray data, including spectral extraction, fitting, and report generation.

CIAO
CIAO (Chandra Interactive Analysis of Observations) is the name for the suite of tools and applications developed at the Chandra X-Ray Center (CXC) for the analysis of data from the Chandra X-Ray Observatory and other missions. Apart from a few Chandra-specific instrument tools, CIAO is mission independent by design and has proven itself useful for the analysis of data from other X-ray and non-X-ray missions.

CHASC AstroStatistics Collaboration
The AstroStatistics collaboration between CXC and the Harvard University's Statistics department has produced a number of programs designed to analyze X-ray data in the low-counts regime. Some of these are already publicly released, and some are in testing stage prior to general release.

Package for the Interactive Analysis of Line Emission (PINTofALE)
A suite of IDL procedures designed to simplify the analysis of high-resolution UV-X-ray spectra, with emphasis on line identification, flux measurement, and reconstruction of plasma emission measure distributions. Many of the routines are completely general and adaptable to other aspects of astronomical data analysis at any wavelengths.

XPA
The XPA messaging system provides seamless communication between many kinds of Unix programs, including X programs and Tcl/Tk programs. It also provides an easy way for users to communicate with XPA-enabled programs by executing XPA client commands in the shell or by utilizing such commands in scripts.

Funtools
Funtools, is a "minimal buy-in" FITS library and utility package. The Funtools library provides simplified access to FITS images and binary tables, as well as to raw array and binary event lists. Funtools utilities provide high-level support for processing astronomical data.

WCSTools
WCSTools is a package of programs and a library of utility subroutines for setting and using the world coordinate systems (WCS) in the headers of the most common astronomical image formats, FITS and IRAF .imh, to relate image pixels to sky coordinates. This software is all written in very portable C, so it should compile and run on any computer with a C compiler.

RVSAO
RVSAO is an IRAF add-on package developed at the Smithsonian Astrophysical Observatory Telescope Data Center to obtain radial velocities from spectra using cross-correlation and emission line fitting techniques.

MicroObservatory Image
MicroObservatory Image is a simple to use, yet powerful astronomical image processing program that works with FITS and GIF files. Works on both Macintosh and Windows platforms.