lib4d_sql is a C library that provides the required functions (connect, prepare, execute, etc.) for writing an SQL client for 4D databases. It uses the public 4D SQL protocol, which is supported by 4D products since version 11. It is already used by the PDO_4D Open Source project, and it might be used to provide others drivers for JDBC, ADO, or ActiveRecord.
php-identity-map is a registry for loaded domain instances. It solves problems that arise when using the Active Record pattern with more than one object that references the same domain entity. The identity map allows you to be confident that your domain entity is shared throughout your application for the duration of the request. This package can store and retrieve objects in persistent storage containers, avoiding the need to have multiple instances of the same object in memory. It can use a mapper class to store objects of a class in a container, e.g. a database table. It can also retrieve the objects from the container, assuring that only one instance of the same object is retrieved into memory.