what is best tool to implemnt uml for .net

I recommend you Visual Paradigm. You can download a Community Edition (free) for non commercial use. Check the website: Visual Paradigm Website
Using this tool you can design UML Diagrams (class diagram, use cases, etc.), database diagrams, components diagram (architecture), etc.

Different UML tools have different pros and cons; which one is "best" depends on what you need. There is a good comparison of UML tools here[^]

Hi,

To create UML diagrams of design of the system either its Class, Sequence or Db design, I would always recommend Enterprise Architect (EA) by sparx systems.
http://www.sparxsystems.com/products/ea/index.html[^]

It has all the features that a Tech designer needs to prepare detailed design. It also comes with an MDX installer which can be integrated with VS2010, so in case you are working with VS2010, its the best in the market.

The best thing is you can always sync up your code with design at any point of time so the design is always updated.

Besides EA, Visio is another tool which you can use for the design.

Hope this helps to make your decision...


with kudos,

Pradeep

What do you mean by implement? Do you want to create code from UML?

Then, IMO, Visio can be used. I have used it a couple of times and found it good. I expect, both are from same vendor and should very well be compatible with each other.

"Best" depends on many factors like your budget, requirements, no. of licenses to purchace etc.

You may need to list down some of these items before someone can give you an idea.

Also check the Tangible Architect solutions. Download a evaluation and check it. It may helps you in reverse and forward engineering.

I recommend Software Ideas Modeler (softwareideas.net[^]).
It's an user-friendly UML tool which supports generation of source code in C# and VB.NET.
It has also a free version.