PBX Hell: 50-Plus Hacks and Tips to Get to a Real Person at Any Corporation in 10 Seconds or Less - VoIP News
This will be helpful sometimeOpenVBX: the Web-based, Open Source Phone System for Business
OpenVBX allows developers to build voice and SMS applications for business, such as toll free phone numbers, call forwarding, voicemail, visual voicemail, voicemail transcriptions, and auto-attendants. It's like Google Voice, but open source and for business.
: the Web-based, Open Source Phone System for BusinessTwilio Cloud Communications: Web Service API for building Voice and SMS Applications
Twilio allows your web application to easily make and receive phone calls and SMS text messages using a simple web service API and basic web programming skills like HTTP, XML, and REST. You can build hosted IVR, PBX and SMS applications with no up front costs and a free trial.
Web Service API for building Voice and SMS Applications
A modern, flexible business phone platform.