I've been listening to a talk Bill Moen gave at the TLA 2004 conference on my MP3 player. (TLA makes CDs of the conference with MP3 files of the talks available for a very reasonable sum.) In it he talks about our end users. Those are the folks walking in during business hours and visiting our Web site. OK, nothing new. Then there are the staff. We have to circulate, weed, preserve, build bibliographies, do collection development, etc. All that makes us users of our own work. Again nothing new, but one aspect we often overlook. Then he mentioned software as an end user. New idea to me, turn on the light. Of course, with Z39.50, OAI, APIs, SRU/SRW, etc. it makes perfect sense. We should include all the interoperability aspects when discussing end users. Making an XML version of our work might make sense to our software end users.