FusionPBX

FreeSWITCH™ is a highly scalable, multi-threaded, multi-platform communication platform. It provides unlimited extensions, voicemail-to-email, music on hold, call parking, call center, call queues, phone provisioning and many other features. It provides the functionality your business needs and brings corporate level phone system features to small, medium and large businesses. Official Release FusionPBX version 5.5 has now been released with many improvements.