1. DigitalPUSH allows you to re-engage visitors and drive them back to your website, from anywhere on the browser, for FREE!

    free

  2. Call or send messages to friends and family members as well as other people who are online. The app allows you to create a message and send it out to multiple devices and pages.

  3. a simple self-hosted server for sending and receiving messages

  4. With CleverPush, website owners can send push notifications to their subscribers even if they are not on the page.

  5. Serverless WhatsApp API made simple

  6. Build and run SaaS and other go-to-market applications faster using JavaScript, GraphQL, and 8base.

    paid Free Trial $8.0 / Monthly (1,000 user accounts, 100,000 API calls.)

  7. spaCy is a library for advanced natural language processing in Python and Cython.

  8. A lightweight message queue for Node.js that requires a Redis server.

  9. nanomsg is a socket library that provides several common communication patterns.

  10. Luigi is a Python module that helps you build complex pipelines of batch jobs.

  11. Run SQL in your browser and chart the results

  12. NATS Server is an open source messaging system for cloud native applications, IoT messaging, and microservices architectures.