The Overture Tool is an open-source tool developed by a network of interested VDM-users all around the world. General information can be found at the Overture website.
Downloads of ready-to-run versions of the Overture Tool are presently hosted on SourceForge; the current version is available here.
It is possible to download development versions from this server. We guarantee nothing about these builds — it is entirely possible that they will not work as expected.
All of the Overture code is hosted on GitHub, under the @overturetool organisation account. Everyone is welcome to grab it, fork it, and contribute.