Open-source One Identity alternatives

Keycloak is an open-source identity and access management server. It lets application teams add authentication and secure services without building their own login system, since Keycloak handles storing users and authenticating them. The project is written in Java, released under the Apache-2.0 license and governed under the Cloud Native Computing Foundation code of conduct.

Keycloak supports standard protocols such as OpenID Connect and SAML, and offers user federation, strong authentication, user management and fine-grained authorization. You can run it from the downloadable distribution using a start-dev command, or use the official Docker image published on Quay for containers and Kubernetes setups. The project provides documentation, a user mailing list and community channels for help, along with guidance for building and testing from source.

authentik is an open-source Identity Provider for modern single sign-on. It supports SAML, OAuth2 and OpenID Connect, LDAP, RADIUS and more, and is designed for self-hosting at any scale, from a small lab to production clusters. A reverse-proxy mode also lets it protect applications that lack native SSO support.

The project positions its enterprise offering as a way for organizations to replace incumbent identity providers (Okta, Auth0, Entra ID or Ping Identity) in large-scale identity management. For installation, Docker Compose is recommended for small and test setups, a Helm chart for Kubernetes suits larger setups, and official templates exist for AWS CloudFormation and a one-click DigitalOcean Marketplace app.

The codebase is mostly Python with Kubernetes tooling, and the license is listed as 'Other' on GitHub because it mixes open-source and enterprise components, so check which features fall under which terms. authentik is a common choice for self-hosters and companies who want to centralize logins across internal tools without paying per-user fees to a hosted identity vendor.

FreeIPA lets Linux administrators centrally manage identity, authentication and access control for Linux and UNIX systems. It provides command-line and web-based management tools that are simple to install and use, and it focuses on ease of management and automation of installation and configuration. The repository is a mirror of the upstream project and is written mostly in Python.

The README lists benefits such as letting users access every machine with the same credentials and security settings, transparent access to personal files from any machine, grouping to restrict services and files to specific users, central management of passwords, SSH public keys, sudo rules, keytabs and access control rules, and delegation of selected administrative tasks to other power users.

FreeIPA bundles well-known open-source components with unified tools: an LDAP server based on the 389 project, a Kerberos KDC based on MIT Kerberos, a public key infrastructure based on Dogtag, Samba libraries for Active Directory integration and a DNS server based on BIND. It can integrate into Active Directory environments through cross-realm Kerberos trust or user synchronization. The code is licensed under GPL-3.0.

WSO2 Identity Server is an identity and access management solution that organizations can run on premises or in their own cloud environment. It is meant to secure applications for external consumers, an internal workforce, business customers and partners, and API access.

Standards support includes OAuth 2.0, OpenID Connect and SAML 2.0, with single sign-on, multi-factor and adaptive authentication. Recent versions add a visual designer for authentication flows, templates for configuring apps and login methods, simplified role-based access control for API policies, and a new authentication API for in-app login. AI-assisted features can generate flows from natural language descriptions and match branding. B2B capabilities include delegated administration and per-customer login options.

The code is Java and Apache-2.0 licensed. For teams that prefer not to operate it, WSO2 points to Asgardeo, a public identity cloud service built on the same technology core, which it says can be tried free of charge.