OASIS stands for "Organization for the Advancement of Structured Information Standards" and the consortium is better known for its work in XmlProgrammingLanguage and WebServices.
According to http://www.oasis-open.org/who/, they have been causing trouble since 1993, two years after IETF proposed "XML media types" (http://web.archive.org/web/20041121161729/ftp://ftp.isi.edu/in-notes/rfc3023.txt), 5 years before XML 1.0 spec was adopted.