A set of Free, helpful, quality User Interface Design elements, icons and styls to design faster wireframes and create better mockup deliverables in Illustrator.

The set contains:

• GUI library – Hundreds vector elements for interface design
• Minimal UI icons set – 260 vector icons for Illustrator
• Styles library – 200 styles to apply in Illustrator

These user interface design elements can be customized easily to your own needs : you can easily resize, color or tweak their appearance.

Free Yahoo Design Stencil Kit

Yahoo Design Stencil Kit version 1.0 is available for OmniGraffle, Visio (XML), Adobe Illustrator (PDF and SVG), and Adobe Photoshop (PNG).

Download Yahoo Design Kit

iPhone PSD Vector Kit

iPhone Starter Kit, a set that comes with several button elements as well as six different iPhone interface options. This pack may be useful for mobile developers and front-end designers who need a professional way to show mock-ups to clients or to work out ideas.

Download iPhone PSD Vector Kit

Handpicked collection of Beautiful, Creative & modern website footer for designers. A very handy pack for design references.

GTK+ is a highly usable, feature rich toolkit for creating graphical user interfaces which boasts cross platform compatibility and an easy to use API. GTK+ it is written in C, but has bindings to many other popular programming languages such as C++, Python and C# among others.

This Free Toolkit for Creating Graphical User Interfaces was initially developed for and used by the GIMP, the GNU Image Manipulation Program. It is called the “The GIMP ToolKit” so that the origins of the project are remembered. Today it is more commonly known as GTK+ for short and is used by a large number of applications including the GNU project’s GNOME desktop.

MochaUI is an open source web applications user interface library built on the Mootools javascript framework.This Free library can be used for making Web Applications, Web Desktops , Web Sites, Widgets and Standalone Windows and Modal Dialogs. MochaUI is made with canvas tag graphics.

Features

• No images. The windows, including their controls, gradients and shadows, are drawn with the canvas tag
• Adjustable rounded corner radius
• Windows can be focused, dragged, resized, maximized, restored down and closed
• Dynamically create new windows on demand
• Fullwindow window size is adjusted if the browser window size changes
• Minimal HTML markup required

MochaUI is compatible and tested in all major browsers.

Requirements: MooTools and Explore Canvas

Website: http://mochaui.com

Demo: http://mochaui.com/demo/

Download: http://code.google.com/p/mocha-ui/downloads/list

This plug-in was inspired by the extJS border-layout, and recreates that functionality as a jQuery plug-in. The UI.Layout plug-in can create any UI look you want – from simple headers or sidebars, to a complex application with toolbars, menus, help-panels, status bars, sub-forms, etc.

Combined it with other jQuery UI widgets to create a sophisticated application. There are no limitations or issues – this widget is ready for production use.

Some Features:

• Simple to use
• Total CSS control
• Collapsable
• Unlimited layout capabilities
• Hotkeys
• Compatible with UI widgets

Requirements: jQuery Framework

Website: http://layout.jquery-dev.net/

Demo: http://layout.jquery-dev.net/demos.html

Download: http://layout.jquery-dev.net/downloads.html

Bad Usability Calendar is a calendar displaying “user interface design tips” with a sense of humor.

It has examples of exaggerated use of fancy Web 2.0 design, cover flow, personalization, pull-down menus and more…

Examples from the tips:

• Don’t require login if you don’t have to
• Offer personalization where it adds value

It is presented in multiple languages, various sizes & PDF format.

Feng-GUI is a free web based service that enables you to view: “which areas of an UI is getting the most attention when an user looks at it in 5 seconds”.

With an artificial intelligence behind, the service generates a heatmap over an image uploaded.

Generated heatmap’s opacity can be changed for a better view & can be viewed in a bigger modal window or downloaded.

Feng-GUI is very handy to get another thought -about a user interface designed- other than the collagues, customers..

Website: http://www.feng-gui.com/