I have found some references to the xeb format using Google. One is a program for Pocket PC that supposedly can read the format.
http://www.teamonesoft.com/en/Products6.htm
Here is a device that apparently also can read the format
http://www.foundertech.com/product/ebooknew.asp
I even found a link to the Apabi site that had something about xeb, but unfortunately it was dead. However the same connection to Apabi Reader can be found here I think (not that good at Chinese)
http://microwolf.net/bbs/dispbbs.asp...D=28147&skin=1
I must admit that I thought Irex were not ready with Apabi support, and that it only would be for the asian market.