He is the founder , chairman and CTO of Digium , an open - source telecommunications supplier most notable for its development and sponsorship of Asterisk .
Mark Spencer is also the creator of Asterisk , a Linux - based open - sourced PBX in software .
Mark Spencer is the creator , chairman and CTO of Digium , an open - source telecommunications supplier most notable for its development and sponsorship of PBX .
Mark Spencer is also the creator of Asterisk , a Linux - based open - sourced PBX in software .