Wekan is available on many platforms: https://github.com/wekan/wekan/wiki/Platforms
a) In Wekan standalone version it's possible to disable self-registration in Admin Panel. There is inviting users, user permissions Admin/Normal/Comment only, but not user management yet:
https://github.com/wekan/wekan/wiki/Features#authentication-...
and in next version it's possible for user to change password: https://github.com/wekan/wekan/blob/devel/CHANGELOG.md
b) In https://sandstorm.io version there is already user management, Google/GitHub/LDAP/SAML authentication etc:
https://discourse.wekan.io/t/sso-passing-variables-through-u...
Newest version of Wekan is coming to Sandstorm in near future, progress is at:
There are issues for having LDAP/Saml/GitHub/Google etc auth for Standalone Wekan, but they are not implemented yet.
https://github.com/wekan/wekan/wiki/Integrations#authenticat...
Sandstorm platform brings LDAP, SAML etc authentication to all apps running on Sandstorm.
Sandstorm has long list of sandboxing and other high-end security features:
https://docs.sandstorm.io/en/latest/using/security-practices...
All of Sandstorm is now Open Source, including Blackrock clustering:
https://sandstorm.io/news/2017-02-06-sandstorm-returning-to-...
For Standalone Wekan, Teams/Organizations/User admin is currently at planning stage: