Qt - Powerful, flexible and easy to use, Qt will help you not only meet your tight deadline, but also reduce the maintainable code by an astonishing percentage.
Google App Engine - A powerful platform to build web and mobile apps that scale automatically.
wxWidgets - wxWidgets: Cross-Platform GUI Library
Dokku - Docker powered mini-Heroku in around 100 lines of Bash
FLTK - Fast Light Toolkit - Fast Light Toolkit (FLTK)
Google Cloud Functions - A serverless platform for building event-based microservices.