Why is Microsoft's e-government system framework similar to Oracle's solutions?

Microsoft's overall e-government framework (used in Qingdao)

Basically, it is also a layer-4 structure:
1. Surface Layer (or display layer, unified portal Support Platform ):
Provides unified access interfaces and Identity Authentication interfaces for various subsystems, and releases new announcements or news;
2. Application Layer:
For each subsystem that is independent or integrated, each has its own business;
3. middleware layer:
It is a unified interface for interaction and connection between the database and the application layer, and can be expanded in a programmable manner. It can be applied to various subsystems and provides a unified interface for the subsystem to operate the underlying unified database center;
4. Data center layer:
That is, the bottom-layer database center. All subsystem operations and stored data are in this unified database. You can search and query data beyond a single database through another subsystem. the database is generally IBM DB2 or infomix, Oracle Oracle10g or other large databases. The database is generally logically centralized and physically centralized or distributed. Generally, XML is supported, comprehensive Security Control and Data security protection.

Microsoft's system includes ad user permission control and SQL Server database at the underlying layer. The mail system is estimated to be exchange, and report services is used for reports.