Output Messenger for Mac is a discontinued, free, and open-source application that allowed users to send and receive messages using the Output Arcade platform. Essentially, it was a dedicated messaging client specifically for communicating within the Output Arcade ecosystem (which itself is a subscription-based platform for virtual instruments and effects). Since Output Arcade has changed its structure and offerings, Output Messenger is no longer supported and likely won[SQ]t function correctly. You[SQ]d need to use other methods to communicate with others regarding Output Arcade now.