Where can I get the single sign-on script for DLE, phpBB, vBulletin and others?

Question

CMS

Where can I get a single sign-on script on engines like DLE, phpbb, vbulletin?
So that when registering on one site (dle), the user can log in with the same data on a neighboring site (phpbb, vbulletin, wordpress, drupal, etc.). Something like openid, but for the script to be hosted and not associated with any services.
Freelance services for emergencies.

Answer 1

The maximum that is possible is the integration of engines. But vryatle this pleasure will be cheap. There are no ready-made solutions on the Internet to combine so many CMS. There are bundles and then only in pairs ...