Comment 2 for bug 1980795

Beside the sys tray integration, I think most of what you expect from 'Mixxx mini' could already be realized by creating a mini skin with one deck (and 'a few' engine adustements).
I fear that both creating a secondary main app or a remote app is a lot of work, and a huge maintenance burden, thus I think a better option is to use what's already there and work towards launching MiniMixxx with 'mixxx --miniMode' in small steps. This allows to have all library functionality (much like Daniel's 'secondary window' approach).

The 'few adjustments' coming to mind:
* make the engine work with one deck only
* make AutoDJ work with one deck
* make AutoDJ keep played tracks in their set position
* add some convenience functions to mimic basic media playersin AutoDJ, e.g.
  map double-click on track in AutoDJ to 'LoadTrackAndPlayFromStart'

Launching 'mixxx --miniMode' would
* load a mini skin
* set some controls to engage 'mini mode' and disable vinyl control and
  other unnecessary functions
* open some interface to add songs to the AutoDJ queue from outside Mixxx

Being able to switch between mini / regular mode at runtime would be the cherry on the cake.