The following table lists the dates for all 4.x releases of the Message Queue product and describes the main changes associated with each release.
Table 1–1 Revision History| 
 Date  | 
 Description of Changes  | 
|---|---|
| 
 May 2006  | 
 Initial release of this document for version 4.0 of Message Queue.  | 
| 
 January 2007  | 
 Initial release of this document for Beta version 4.1 of Message Queue. Adds description of JAAS support.  | 
| 
 April 2007  | 
 Second release of this document for Beta version 4.1 of Message Queue. Adds high availability feature.  | 
| 
 September 2007  | 
 Third release of this document for customer ship. Adds description of support for Java Enterprise System Monitoring Framework, fixed C ports, bug fixes, and other features.  |