ConceptDraw WebWave is a software for web site/application prototyping and design, page mocking-up and site-mapping.

Key Features:

Powerful Drawing Tools
ConceptDraw offers a set of vector drawing tools that can rival a professional illustration program.

Alpha-channel (transparency)

Smart Connectors

Flexible Interface

Quick-and-easy access to main tools and settings with customizable toolbars and floating dialogs let access main tools and settings quickly and easily.

Libraries & Wizards
ConceptDraw WebWave goes with dozens of collections of common shapes to help you create a number of different types of diagrams, and drawings.
ConceptDraw WebWave includes the following wizards: Website mapper, Site File Structure Scanner, Site Prototype Builder, To-Do Lists generator, Color Scheme Generator, Gantt-Chart Wizard

Styles
Styles are visual elements that define the look of shapes in your document.

MS Visio Support

Intelligent Shapes
ConceptDraw shapes are highly customizable.

Built-In Script Language
The built-in script language - ConceptDraw Basic - and support for the open XML for ConceptDraw format, as well as a number of other formats provides developers with powerful means of building complex customized solutions based on the ConceptDraw WebWave graphics engine.