Astah is a lightweight UML editor integrated with ERD, DFD, CRUD and Mind mapping features for software developers.Developers, analysts, testers and managers can communicate with one another effectively using astah diagrams because all the diagrams are consistently stored in one model.

Besides the standalone editions, "astah share"(a web server edition) will boost the communication by providing a web-browser view of the shared diagrams so that the team can exchange comments like social network services.
Features:
Improvements of operation
-Create a model by double-clicking on the Diagram Editor
-Up/Down key can select models inside the models in the Diagram Editor
-[Close] button on Diagram Editor tab
-List of Diagram lists on Diagram Editor, etc.

Requirement Diagram
professional supports new features to offer you to use requirements and other models relating to SysML. It visualizes the gap between on-going-process and what it should be done in the project by creating Requirements and TestCases and relationships between them and managing the Requirement Diagram

New model "NEST"
This model represents a nest relationship between namespaces such as Packages and Classes

Orthogonal Regions in Statemachine Diagram
Now you are able to represent Orthogonal Regions in Statemachine Diagram.

Suggest Feature
Suggest Feature which suggests you what model to draw is newly implemented. Models will be suggested when you mouse over models

Whats New:
Updates: official site does not provide any info about changes in this version