The standalone version of xstar is available as a gzipped and tarred file on the xstar website
http://heasarc.gsfc.nasa.gov/docs/software/xstar/xstar.htmlThe source code is available along with compiled executables for several machine architectures.
The installation is the same as for the full heasoft:
http://heasarc.gsfc.nasa.gov/docs/software/lheasoft/install.html
In more detail, you follow these instructions, but obviously the tarfile is named xstar22src.tar.gz rather than what is given in the heasoft instructions, and the directory that appears when it is untarred is called heasoft, not heasoft-6.9. A condensed version of what you need to do is as follows:
2) In the directory in which you want to install the software, unpack the file you downloaded in step 1 using e.g.: gunzip -c xstar22src.tar.gz | tar xf - This will create a heasoft/ directory containing the software distribution. 3) Configure the software for your platform (necessary for both binary and source downloads): cd heasoft/BUILD_DIR/ and run the main configure script, which will probe your system for libraries, header files, compilers, etc., and then generate the main Makefile. To produce a default configuration, the configure script may simply be invoked by (we recommend capturing the screen output from configure as below): ./configure >& config.out & (C Shell variants) ./configure > config.out 2>&1 & (Bourne Shell variants) 4) Start the build process. We strongly recommend that you capture all output into a log file. Then, if you need to report a problem, please send us the ENTIRE log file. And since it may take some time to run (from minutes to hours, depending on the speed of your system) we recommend that you build it in the background: make >& build.log & (C Shell variants) make > build.log 2>&1 & (Bourne Shell variants) To check on the build progress in real-time (if you wish) try: tail -f build.log 6) Perform the final installation of the executables, libraries, help files, calibration data, perl scripts, etc, by executing: make install >& install.log & (C Shell variants) make install > install.log 2>&1 & (Bourne Shell variants) This will create an appropriately-named system-dependent directory, e.g. sparc-sun-solaris2.9/, either under heasoft/ or, if you specified a prefix argument to configure, in the directory you selected at that time.