HEAsoft is the generalized term for the full set of software distributed from the HEASARC, incorporating all of the newly-developed software in the HEADAS environment (e.g. Swift) as well as all of the traditional HEASARC software (FTOOLS, XANADU, XSTAR).
Vesion 6.15 is available for every user. Free for download []
(because limitation of download speed, can be download from GSFC very long)
It is needed to define variable.
and then execute inicialization script
(analogically can be done initialization in C-shell by $HEADAS/headas-init.csh)
Filip Münz, Matúš Kocka, Tomáš Rebok (firstname.lastname@example.org)
On-line manual for XSPEC can be found here