It was designed by amateur radio operator Pawel Jalocha, SP9VRC, to be an open communications standard.
Like all amateur radio communications modes, this protocol uses open transmissions which can be received and decoded by anyone with similar equipment.
It can be used to interconnect local VHF AX.25 packet networks over transcontinental distances.
Q15X25 is a digital signal processor-intensive mode designed to pass AX.25 packets on HF with speed and reliability much greater than traditional HF ARQ modems.
Typically the DSP based receiver and transmitter modulator or codec is implemented as PC software that uses a sound card to connect directly to an SSB transceiver.