Mustache.js - Minimal templating with {{mustaches}} in JavaScript - janl/mustache.js
Twinme - Twinme – Private Messenger is a free, secure, instant, and high-definition messaging app that protects your privacy along with giving you full control over each of your relationships and contents.
EJS - An open source JavaScript Template library.
Textra - Textra is a seriously beautiful, feature rich SMS and MMS app.
FLAVE - Flave was created to bring ASP.
Material Messaging - Material Messaging is a beautiful communication app that lets you send and receive SMS and MMS messages using the intuitive interface while giving you complete control over every aspect of your messaging experience.