When JMRIDemo quits, it fails to stop advertising mDNS services that are running. I do not know if this issue applies to all apps, nor do I know if this issue is specific to Mac OS X (where I am encountering it). This issue applies to versions 2.10, 2.11.5, and the CVS trunk.
Steps to reproduce:
1) Start the mini web server in JMRIDemo.
2) Confirm that the JMRI (_http_) service is browsable using a web browser.
3) Quit JMRIDemo.
4) Use the Safari web browser to browse Bonjour services. Note that the JMRI service continues to be discoverable, although JMRI is no longer running.