The XMM-Newton Extended Source Analysis Software package (XMM-ESAS) is
developed at the NASA/GSFC 
 
XMM-Newton Guest Observer Facility (GOF)
in cooperation with the XMM-Newton SOC and the Background Working Group.
XMM-ESAS allows the user to model the quiescent particle background for both
spectral and spatial analysis of EPIC MOS observations. It produces
background spectra for user-defined regions of the detectors and background
images. The output files are FITS standard and can be used in spectral fitting
packages (e.g., Xspec) or with FITS image display software (e.g., fv or ds9).
XMM-ESAS is based on the software used for the background modelling
described in 
Snowden, Collier & Kuntz (2004, ApJ, 610, 1182). 
The XMM-ESAS package is integrated in SAS, as of version 9.0. XMM-ESAS 
supports the analysis of pn and MOS observations. XMM-ESAS documentation 
can be found at the SAS Package documentation web pages:
    
http://xmm.esac.esa.int/sas/current/doc/esas/index.html 
or at the SAS Portal web pages:
    
http://xmm.esac.esa.int/sas/current/howtousesas.shtml 
For XMM-ESAS related questions, please
contact the XMM-Newton Helpdesk through the following page
    
http://xmm.esac.esa.int/external/xmm_user_support/helpdesk.shtml
or visit the NASA XMM-GOF at
    
http://heasarc.gsfc.nasa.gov/docs/xmm/xmmhp_xmmesas.html
which provides also a section on 
Warnings and Watchouts.
Suggestions for improving the software or documentation are also
welcome.