What to choose instead of MS AD for the office where is a hodgepodge of Linux / Windows / Mac?

Question

LDAP

Hello.
In an office where Linux (80%) / Windows 10% / MAC 10% is used, it is required to deploy a single point of authorization and user management.
The task is a single point of authorization and subsequent access to resources: - mail, redmine, Internet, network balls, possibly client-server applications, etc ...
MS AD is not desirable - it costs money ... (although there is experience and closes all tasks)
OpenLdap - no experience. Are there solutions out of the box for review? Is it possible to complete all tasks on its basis?
SAMBA 4 - as an option?
389 directory server - no experience. What do you think?
Maybe something else?

Answer 1

Samba4 is, as far as I know, "AD without Microsoft". I haven’t tried it myself, although I always want to find time for this :) You can try IPA - this seems to be a solution that RedHat uses (although I haven’t seen paid redhat servers live, of course)

Answer 2

For openldap I wrote 3 articles (for myself), if anyone is interested 1 2 3

Answer 3

AzureAD? True, this also requires money, but still less.