Table of contents

Applications on GOV.UK

The publishing platform of GOV.UK consists of at least 49 separate applications. Most of them are built using Ruby on Rails.

You can download this data as JSON, or download this data as CSV. In Google Spreadsheets, use the following formula:



Applications are hosted on an infrastructure configured using puppet. They are deployed using capistrano scripts.

Frontend apps

Frontend apps render content to visitors to For example, a HMRC manual page is rendered by an application called manuals-frontend.

You can use the chrome extension to find out which application is rendering any given page.

All frontend applications use a Ruby gem called slimmer, which wraps the generated HTML into a layout with GOV.UK styling. To avoid having to update all applications for a global design change, slimmer pulls in the actual ERB templates from the “static” application, which also serves stylesheets, javascript and images.

Publishing apps

Publishing apps are used by editors to publish content to GOV.UK. For example, specialist-publisher publishes specialist documents.

The apps are secured by behind a single signon system. They use an omniauth adapter called gds-sso to authenticate the user. The styling of the apps are shared using a gem called govuk_admin_template.