GOV.UK Platforms product page describes some of the platforms that Government Digital Service offers and can be accessed on platforms.service.gov.uk. There is no software required to be installed to get the local version working, such as npm or docker.
This was based on the product-page-example and uses the GOV.UK Frontend. There is a sign up form which links to a Mailchimp account.
Unless stated otherwise, the codebase is released under the MIT License. The documentation is © Crown copyright and available under the terms of the Open Government 3.0 licence.