Axure RP Pro is a dedicated tool for prototyping web sites and web applications. It's based on concepts known from Visio and web design tools, and elegantly combines the best of the two worlds. Interaction designers have suffered from the fact that there have been no decent software tools on the market dedicated to prototyping. Those of us who didn't stick with the pen, paper, scissor and glue stick method of paper prototyping, have had no other option but to use and adapt tools designed for other purposes, such as Visio, Dreamweaver, PowerPoint, and Photoshop. Axure have set out to change this. Their Axure RP Pro is a dedicated web prototyping tool. All it does is prototyping, and it does it quite well.

The good:
- Drag and drop widgets onto a grid (as you might know it from Visio)
- Generate prototypes in a format that behaves like real web pages (i.e. you can interact with forms and pages can scroll)
- Save time on repetitive changes by using custom widgets and templates
- Simulate rich interactivity by showing and hiding layers
- Automatically generate user interface specifications

The bad:
- You can't navigate your pages inside Axure by clicking links and buttons
- Somewhat expensive

http://"http://axure.com/"