InfluxDB v0.4.0 is a major release with significant changes to its underlying data storage, requiring users to upgrade or risk losing their existing data. The new version introduces various features such as custom dashboards and support for multiple programming languages through client libraries. Additionally, the project has seen contributions from the community, including command line interfaces, backend integrations, and deployment options. To address the impending release, InfluxDB is offering a migration service for users who want to preserve their existing data. The company also invites users to participate in a hackfest scheduled for December 2nd, where developers can collaborate on new projects and share their work with the community.