You can find the official changelog for the main UpStream plugin in 2 places:

- Github: [click this link](https://github.com/upstreamplugin/UpStream/releases)
- WordPress.org: [click this link](https://wordpress.org/plugins/upstream/#developers)

There are also changelogs available for each UpStream extension:

- [Changelog for the Calendar View Extension](https://support.upstreamplugin.com/hc/upstream-plugin/articles/changelog-calendar-view)
- [Changelog for the Copy Project Extension](https://support.upstreamplugin.com/hc/upstream-plugin/articles/changelog-copy-project)
- [Changelog for the Custom Fields Extension](https://support.upstreamplugin.com/hc/upstream-plugin/articles/changelog-custom-fields)
- [Changelog for the Customizer Extension](https://support.upstreamplugin.com/hc/upstream-plugin/articles/changelog-customizer)
- [Changelog for the Email Notifications Extension](https://support.upstreamplugin.com/hc/upstream-plugin/articles/changelog-email-notifications)
- [Changelog for the Frontend Edit Extension](https://support.upstreamplugin.com/hc/upstream-plugin/articles/changelog-frontend-edit)
- [Changelog for the Project Timeline Extension](https://support.upstreamplugin.com/hc/upstream-plugin/articles/changelog-project-timeline)