patent number 8,301,595, for accessing an LDAP server over AMQP. In January 2008 I provided to the AMQP Working Group, including Red Hat, the Digest-AMQP spec, "a way to integrate WWW servers and LDAP servers over an AMQP network." Here's the GitHub repository. Red Hat's patent 8,301,595 was filed two and a half years later, on June 14, 2010. In 2009 I wrote about another Red Hat patent on AMQP. That time, Red Hat said required patents would be made available royalty-free, but then as now, the patent was not on the standard but of a common use around it."
Link to Original Source