18.0.153 makes some new things possible with the command line and web service.
I was looking for a way to make it really easy to get background music playing at home.
This batch file runs the program, stops what's playing, links zones (you need zones named 'Kitchen' and 'Living Room'), sets the volume, then starts Play Doctor playing.
REM --------------------------------
REM JRiver One-Click Play Batch File
REM --------------------------------
REM Make sure MC is running
MC18.exe
REM Stop playback of anything that might be playing
MC18.exe "/MCWS/v1/Playback/Stop?Zone=Kitchen&ZoneType=Name"
MC18.exe "/MCWS/v1/Playback/Stop?Zone=Living Room&ZoneType=Name"
REM Link zones
MC18.exe "/MCWS/v1/Playback/LinkZones?Zone1=Kitchen&ZoneType1=Name&Zone2=Living Room&ZoneType2=Name"
REM Set volume for each zone
MC18.exe "/MCWS/v1/Playback/Volume?Zone=Kitchen&ZoneType=Name&Level=0.65"
MC18.exe "/MCWS/v1/Playback/Volume?Zone=Living Room&ZoneType=Name&Level=0.75"
REM Start Play Doctor playback
MC18.exe "/MCWS/v1/Playback/PlayDoctor?Seed=Easy Listening&Zone=Living Room&ZoneType=Name"
Someday I'd like to get it so my phone could wake up the computer and run the script with a single click. Gizmo already does the wake up part, so this might not be too hard.