The SCIM standard provides a standardized mechanism to create and manage user accounts. This helps portability (moving users across vendors) and interoperability by offering a common way how administrators and users themselves can manage quota, email aliases and other options.

scim-server-php is a library which can be used to easily add support for the SCIM user provisioning standard (RFC 7643/7644) to existing systems. The library is already used in extensions for PostfixAdmin and Nextcloud.