Next major Major release version 4.0 will have has stable support for multiple external user directories. At the minimum, the The following new user directories will be are included (in alphabetical order):
Apple ID
Facebook
Google
Microsoft Account (consumer-grade accounts)
Microsoft Azure AD
MPASSid (OpenID Connect based variant)
Trivore ID (Trivore Identity Service, OpenID Connect)
Generic OIDC (OpenID Connect)
Generic SAML (Security Assertion Markup Language)
...
For completeness sake, already existing and supported user directories are also listed here:
Generic LDAP (Lightweight Directory Access Protocol)
Microsoft AD DS
Microsoft AD FS
suomi.fi SAML
simple REST API for cross-platform and cross-vendor account migration
In addition to features listed above, there is a technological change: Java version 11 will be used instead of Java version 8 starting version 4.0.Target for this release is spring 2021.