SSO Tax

Single-Sign-On (SSO) options are used for authentication with applications, and are often built on standards like LDAP, OIDC and SAML.

For projects with an open-core setup, where some features are provided outside the FOSS licensed works, SSO options are a common target part of the non-FOSS offerings. This is commonly referred as a “SSO Tax”. Many find this problematic as they see SSO as a core security feature, instead of an added luxury.

Projects which do this will state what such features are needed by enterprise users, who are able to pay to fund development of the project, but over the years SSO has also become more common in smaller business and self-hosting scenarios too.