FreeMarker VS keycloak-ui

FreeMarker is a template engine, it allows to generate text output based on templates and dynamic data. It is similar to Mustache, Handlebars, Thymeleaf and other template engines. Templates are written in the FreeMarker Template Language (FTL) that supports conditional blocks, iterations, formatting, and many other capabilities.

Getting back to our two main technologies....we have implemented Keycloak as our Identification and Authorization Management system (IAM). However, as these things go, Keycloak has its own tech stack. One of the technologies, of course, is the language they used, which is Java. And being it is Java, they chose to use a templating engine called Freemarker.

The project I was working on was a website using Magnolia as their CMS. It uses the Freemarker templating engine under the hood. Essentially these are super-powered HTML files, which give you access to the CMS content. You can still use all of the HTML tags you want, including the

You can use Java for Backend and Frontend. A relative new kid on the block for Frontend is Qute. The general keyword you are searching for is Java Templating Engine. Specific examples would be Thymeleaf or FreeMarker. There are some framework, which offer a lot more than templating like Vaadin or Wicket. Some are just specifications like Jakarta Faces with some of their implementations MyFaces or Mojarra.

Keycloak uses FreeMaker to store and render templates. Read more about how Keycloak manages its themes in the official documentation.

For some component types, there is also the possibility to use a Freemarker template instead for more complex UI components. In this case, it will look like this:

From sing-up page to admin portal, you can customize pretty much any part of the UI using custom themes. Themes are developed using Freemarker Templates and it's all documented here.

Yes, but I expect more issues to come. Especially due to the removal of the old admin-console there might be some strange behavior with existing client / realm configurations where the new admin-console works a bit different then the old one..., e.g.: https://github.com/keycloak/keycloak-ui/issues/4450 and many more...

In Keycloak 19 there is a bug in interface that does not allow opening settings for authenticators. Refer to this issue.

We're actually working on a new version of the Administration UI at the moment (I'm one of the devs) so this is useful feedback. We're looking for folks to try it out, so take a look at https://github.com/keycloak/keycloak-admin-ui/.

You can try it out on the latest Keycloak by passing the --features=admin2 flag on startup.

I had to use keycloak in the past as the authentication service for a work app. Keycloak you can pull the docker image and start it up fairly easy. The UI is built in React with Typescript here https://github.com/keycloak/keycloak-admin-ui.