Acorn is an easy-to-use but still relatively feature-filled image editor that provides a lower-cost alternative to professional editing programs. With its slimmed-down interface--just a single palette and a document window--Acorn feels much like Apple's iLife applications, but it still provides a full array of editing features, including multiple layers (with masks), vector shapes, filters (such as tilt-shift, plus support for Quartz Composer compositions), blending, gradients, text and drawing tools (including a Brush Designer for custom brushes), and a hex color picker.
What makes this app most appealing is its ease of use and raw speed: Acorn takes full advantage of Snow Leopard (which is required), opening, saving, and performing (and even undoing) many operations faster than ever. It also includes countless thoughtful touches, from support for AppleScript to an ingenious keystroke screenshot feature, which instantly opens screen caps in Acorn with automatic layers already applied for different windows and objects such as the Dock and menu bar.
With Version 3, Acorn now has more than 50 new features and refinements, including Layer Styles, so you can apply nondestructive effects with the ability to change your mind later. Multistop Live Gradients give you several options for creating complex gradients beyond the original two styles. You also get several new filters, the ability to quickly rotate text and shapes, and you can import or export Adobe Photoshop files. Frankly there are far too many new tweaks to list here, but it's clear the developers are very active with improving an already great product.
If you're a professional (or you just want more heavy-duty tools or a more flexible interface), Acorn isn't for you. But for users with more modest image-editing needs, Acorn is an excellent value with a solid feature set. With this latest version update, Acorn is even better.