For questions about the BizTalk Health Monitor, the successor to the MBV (Message Box Viewer).
The BizTalk Health Monitor is a MMC snap-in, used to monitor the health of your BizTalk environment. BHM is based on the same engine as MBV. The snap-in can be added to the existing BizTalk Administration Console or can be run individually in its own MMC window.
It can be downloaded from BizTalk Health Monitor v4.2
Further details in this blog post