Jasmin SMS Gateway - Jasmin is a very complete open source SMS Gateway with many enterprise-class features such as:
Mobiniti - Mobiniti offers a mobile marketing platform for clients to invite customers to engage with their brand through SMS via their mobile phone.
Ozeki NG SMS Gateway - Ozeki NG SMS Gateway is a powerful, reliable and flexible SMS Gateway application.
Pyze - Pyze utilizes machine learning to understand user behavior and automate user engagement so...
Kannel - Open Source WAP and SMS Gateway
Textmagic - The all-in-one solution for all your business texting needs - marketing campaigns, two-way SMS chats, reminders, notifications, and internal staff communication.