SQL Server Management Studio Plugin for Diagrams

Is there any plugin for SQL Server Management Studio which add more functions and ease of use in database diagrams.

How do I create a database diagram in SQL Server Management Studio?

To create a new database diagramIn Object Explorer, right-click the Database Diagrams folder or any diagram in that folder. Choose New Database Diagram on the shortcut menu. The Add Table dialog box appears. Select the required tables in the Tables list and click Add.

How do I show a diagram in SQL Server?

In Object Explorer, expand the Database Diagrams folder. Double-click the name of the database diagram you want to open. Right-click the name of the database diagram you want to open, and then choose Design Database Diagram.

Sadly, no. The current modelling tool is called "Davinci" and has remain essentially unchanged since it was introduced in SQL 7.0, circa 1997.

I suspect Microsoft is intentionally not releasing better modelling tools, perhaps as an anti-trust settlement or at least good-will. They could easily do a lot of damage to the modeling-tool software market by including a decent one with SQL Server for free. That is just my opinion, however.