Development was first started as an adapter on top of the Millstone 3 open-source web framework released in the year 2002.
By the end of the year 2007 the proprietary client-side implementation was abandoned and GWT was integrated on top of the server-side components.
The first production-ready release of IT Mill Toolkit 5 was made on March 4, 2009, after an over one year beta period.
On September 11, 2008, it was publicly announced[4][5] that Michael Widenius–the main author of the original version of MySQL–invested in IT Mill, the Finnish developer of Vaadin.
It added a channel for distributing add-on components to the core Vaadin Framework, both for free or commercially.
Vaadin Flow features a server-side architecture which means that most of the UI logic runs securely on the server reducing the exposure to attackers.
These components include a server-side Java API (Vaadin Flow) but can also be used directly in HTML documents as well.