Flask started as a project to show you how you can build your own framework on existing Python toolkits. Actually, Flask started as an April Fool's joke in 2010. Several microframeworks had been appearing in the Python community, offering their own set of interfaces to build web services and applications entirely in one
.py file. Having built Werkzeug (a web programming toolkit) and Jinja (a templating engine), Armin Ronacher zipped these two projects, put the zip file base64-encoded into a
.py file, added a few small functions, and called it the Denied microframework.
The April 1st marketing site for Denied included a working "Hello World" application in a few lines of code, a spoof screencast, some bogus testimonials, zero documentation, ...