Jasmin SMS Gateway - Jasmin is a very complete open source SMS Gateway with many enterprise-class features such as:
Zeplin - Collaboration app for UI designers & frontend developers
Kannel - Open Source WAP and SMS Gateway
Pamela for Skype - A versatile and easy to use Skype audio and video recording software. Features
Bulk SMS Services - Sending Bulk SMS to the customers will engage the customers with your business and new offers.
ActiveWords - Auto correct on steroids