All available pac4j implementations:

All pac4j implementations offer similar features:

Spring Web MVC
(Spring Boot)

Jakarta EE
(Servlet)

Spring Webflux
(Spring Boot)

Shiro

Spring Security
(Spring Boot)

Play 2.x/3.x

Vertx

Spark Java

Ratpack

JAX-RS

Dropwizard

Javalin

Undertow

Jooby

http4s

Also available, on an older pac4j line:

Lagom
(pac4j 3.x)

Pippo
(pac4j 2.x)

Akka HTTP
(pac4j 5.x, archived)

Products that embed pac4j:

CAS server

Syncope

Knox