This is quite nice!
I found the name zenta slightly inconvenient to remember and type, so I renamed the executable to 'relax', but the help messages still say 'zenta'. As a small fix, maybe you can make the help messages print argv[0] as the executable name?
Great idea! Just fixed this. Now when you rename zenta to relax, all help messages automatically show "relax" instead of "zenta". Available in v0.3.2. Thanks!