Digium has named a new CEO to replace the open source PBX maker's founder, Mark Spencer, who will now become the company's chairman and CTO. Spencer wrote the code for the PBX, known as Asterisk.

Danny Windham, who was COO of network infrastructure vendor Adtran, will take over as CEO about five months after Digium scored US$13.8 million in venture funding intended to better market the company's low-cost PBX.

Digium has outlined a strategy of enhancing the PBX software in-house and licensing it to other vendors. Digium and its investors say VoIP is blossoming and want to infuse cash into the company so it can attract as many customers as possible during this growth period.

Windham had served at Adtran since 1989, when Adtran bought a company that he co-founded called Processing Telecom Technologies.

He helped found Adtran's enterprise networks division, and served as the company's senior vice president and a director. He is also chairman of the board of 3-GIS, a systems integration company specializing in automated mapping and facilities management. "His operational experience will allow me to focus more time on the customers and the technologies that will accelerate Digium and Asterisk," says Spencer.

Digium also announced the appointment of Steve Harvey as vice president of sales worldwide. Like Windham, he worked at Adtran previously, where he was vice president of channel sales and competitive service providers.