VoIP Drupal is an innovative framework that brings the power of voice and Internet-telephony to Drupal sites. It can be used to build hybrid applications that combine regular touchtone phones, web, SMS, Twitter, IM and other communication tools in a variety of ways, including:
VoIP Drupal is an open source project that is under continuous development. If you would like to get involved or simply ask questions, discussions are taking place on the VoIP Drupal Group and at the VoIP Drupal chat room. You can find the source code and additional information in the VoIP Drupal project page.
The VoIP Drupal platform has originally been conceived and implemented by the MIT Center for Civic Media (http://civic.mit.edu/).