Dialogflow - Conversational UX Platform. (ex API.ai)
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
HelpDocs - Educate your users with a super simple knowledge base that’s built for teams just like yours.
Botpress - Open-source platform for developers to build high-quality digital assistants
phpMyFAQ - phpMyFAQ is a world’s most popular mobile-friendly, feature-rich and open-sources FAQ software that uses PHP 5.