Software Compatibility
There are now three software systems in widespread use in high energy astrophysics.
CIAO for Chandra, SAS for XMM-Newton, and HEAsoft for ROSAT, ASCA, RXTE, BeppoSAX, and earlier missions.
In the next few years we will have Integral, Swift, Astro-E2, and GLAST.
Interoperability will become more important