It is designed to be simple for beginners and powerful for professionals.
IrfanView seeks to create unique, new and interesting features, unlike some other graphic viewers, whose whole "creativity" is based on feature cloning, stealing of ideas and whole dialogs from ACDSee and/or IrfanView! (for example: XnView has been stealing/cloning features and whole dialogs from IrfanView, for 10 years).
IrfanView was the first Windows graphic viewer WORLDWIDE with Multiple (animated) GIF support.
One of the first graphic viewers WORLDWIDE with Multipage TIF support.
The first graphic viewer WORLDWIDE with Multiple ICO support.