Flask Developer(s) Armin Ronacher Initial release April 1, 2010 (2010-04-01) Stable release 0.12.2 / May 16, 2017 (2017-05-16)[1] Repository https://github.com/pallets/flask, git://github.com/mitsuhiko/flask.git Written in Python Operating system Cross-platform Type Web framework License BSD Website flask.pocoo.org