OASIS is an XML industry group devoted to providing vendor-independent information about what is happening in the XML business. It is a consortium of companies interested in using XML to solve business problems. Most of these companies provide products that support XML to some extent or another, but OASIS also includes XML users.
The best resource on the OASIS site at http://www.oasis-open.org, is The XML Cover Pages, which (at the time of this book's publication) is maintained tirelessly by Robin Cover. Robin has reported on the SGML business for years, so was well positioned to cover the XML business since people first started talking about it.
The XML Cover Pages is updated daily—sometimes several times a day—and provides information not only on news releases from different companies, but also on much of the academic and standards work done around the XML standard.