Wireframing is a crucial step in   as it allows for rapid prototyping and helps to pinpoint potential problems early in the process. It can be invaluable to have a visual representation of content, hierarchy and layout.

This post highlights 10 of the best free wireframing tools available, including standalone applications, web-based tools and browser add-ons.

If you’re partial to a particular wireframing tool available for free download, let us know in the comments.

• Lumzy (recommended)
• Cacoo (recommended)
• Mockingbird
• Lovely Charts
• Gliffy
• Mockflow
• Pencil Project (recommended)
• SimpleDiagrams
• Denim
• Website Wireframe

Reference: http://mashable.com/2010/07/15/wireframing-tools/