VOIP could be headed to your office phone, thanks to a pile of VC money that just landed in the lap of Digium. Digium makes Asterisk, an open-source software package that can turn any PC into a telephone switch, substituting VOIP-powered service for a conventional office-phone PBX setup. Because Asterisk is open-source, it's increasingly popular with VOIP software and hardware makers, turning into "a rebel yell for telecom hackers," writes Om Malik on GigaOm. Indeed, Asterisk has become the Linux of VOIP -- a software platform that provides the basic infrastructure code for VOIP products, letting developers focus on more creative features.

But the infusion of $13.8 million from Matrix Partners could seriously dent the open-source community's enthusiasm for building VOIP products on top of Asterisk. Digium founder Mark Spencer tells Malik he wants to use the money to move up from just selling and supporting the basic Asterisk software to selling its own Asterisk-based products to large corporations. That would put Digium in competition with other Asterisk supporters like Fonality, Malik notes.

Preston Gralla at the Networking Pipeline blog seems just fine with the prospect of Digium becoming a supplier of more than just basic VOIP infrastructure software. Inertia, he writes is the only thing keeping companies from dumping their PBX machines for VOIP gear: "In time, Asterisk or software like it will ultimately run most [office phones], and this round of VC funding just brings that day closer."