History
Origin
Keycloak started in 2014, founded by Bill Burke and Stian Thorgersen. It began as a project in the Red Hat and WildFly community and became the upstream for the Red Hat build of Keycloak. The goal was a single server that handled authentication and SSO for applications through standard protocols, so each app would not reimplement login. See the CNCF blog and Wikipedia.
Timeline
| Year | Milestone |
|---|---|
| 2014 | Bill Burke and Stian Thorgersen found Keycloak in the Red Hat / WildFly community (Wikipedia) |
| 2022 | Keycloak 17 makes the Quarkus distribution the default, replacing the WildFly app server (migration doc) |
| 2023 | CNCF accepts Keycloak as an Incubating project on 2023-04-10 (CNCF blog) |
| 2026 | Release line is 26.x; latest is 26.6.3, dated 2026-06-04 (releases) |
How it evolved
The largest shift was the move off WildFly. Until Keycloak 17 the distribution was a WildFly application server configured with XML and jboss-cli. Keycloak 17 (February 2022) made the Quarkus-based distribution the default. Configuration collapsed to a single config file plus CLI arguments and environment variables, and the server adopted a two-phase model: kc.sh build fixes build-time options, then kc.sh start applies runtime settings such as database, hostname, and TLS (migration doc, n-k.de).
The WildFly distribution was supported through Keycloak 20 and then removed entirely. The new Kubernetes Operator assumes the Quarkus distribution (migration doc).
The other major change was governance. Keycloak joined the CNCF as an Incubating project on 2023-04-10. At acceptance the project reported over 15,000 GitHub stars and the keycloak.org site over 150,000 monthly visits (CNCF blog).
Where it stands now
Keycloak ships frequent minor releases on the 26.x line, with 26.6.3 released 2026-06-04 (releases). It is a CNCF Incubating project (CNCF project page) and remains the upstream for the Red Hat build of Keycloak.