Jasmin SMS Gateway - Jasmin is a very complete open source SMS Gateway with many enterprise-class features such as:
SendSMSnow - SendSMSnow is one of the best services over the internet that lets the users to send free SMS in any part of the world in addition to India.
Ozeki NG SMS Gateway - Ozeki NG SMS Gateway is a powerful, reliable and flexible SMS Gateway application.
AFreeSMS - AFreeSMS is a free web-based service that allows you to send unlimited free SMS messages online, no need to register, just type your message and send unlimited SMS to anywhere around the world for free.
Bulk SMS Services - Sending Bulk SMS to the customers will engage the customers with your business and new offers.
Indyarocks Free SMS - Indyarocks Free SMS is listed among the most popular websites in India that offers their users to send as many SMS as they want.