Acorn 8.2 is out. You can use either the Acorn ▸ Check for Updates… menu item, or use the App Store to update if you purchased it from there. The full release notes are available as well.

Here are my favorite things:

Export Gets Improvements Including Image Diffing

When I wrote the new image diffing features for Retrobatch, I knew I wanted to bring those to Acorn as well. Acorn 8's Export window now has the option to show differences as a highlighted overlay between the original and exported image. I've also brought over the split view as well.

When I wrote the new diff view, I knew I wanted to have it shared between the two apps, and I did a lot of work to make sure all of Acorn's main canvas features went into it as well. So things like overscroll, zooming to where the cursor pointer is, click-drag to move, shared shortcuts for zooming, deep image support, wide gamut support, etc. were all there. It was super gratifying to have that just work.

And that new canvas was so nice, I ended up using it in other locations in Acorn. The RAW Import window gets the new canvas, so does the Image ▸ New View… window. I've even added a mostly hidden new action in the Command Bar called "Compare Two Front Windows" which will bring up a new diff window between two images you have open.

Non-Destructive Linear & Radial Multi-Stop Gradient Filters

This is a feature I've wanted for years, and while I've always had the idea in my head how to do it, I just always kept pushing it off for some reason. At some point this past month, I think I just got tired of seeing it on the list, and finally decided to give it a proper go.

I'm pretty happy with how it turned out, and how performant it is. I even did a bit of extra work to make sure there's some dithering in there for the linear gradient, so you won't get any annoying color banding with certain colors.

Lots of Little Things, Thanks to Some Torn Ligaments

So as I was walking out of the climbing gym a few weeks ago, I stepped off a curb, caught an edge in the ground with my foot, and rolled my ankle. There was a pop, myself on the ground, and a lot of pain. The end result was me moving around on crutches for a while and not a whole lot to do but sit with my ankle wrapped and elevated. (I thought I had broken it, but X-rays said otherwise. Apparently I'm a bit of a wuss?)

So I took the opportunity to whittle away at little things, and even add some of my own personal features.

• The blend mode popup now shows a little icon next to each item with a little representation of what each blend mode does. This is super informative if you have no idea what some of these blend modes will do.
• Smart Layer Export now has an option for shared backgrounds between exported layers.
• Command-Option-J is a new shortcut for duplicating the currently selected shape(s). You can also use the Quick Process menu to copy a selected shape a specific amount, but sometimes you just want to duplicate something quickly.
• Zoom modifiers when using the panning tool via the space bar. You can now press the space bar and then the command key to switch to the zoom tool (or use space bar + command + option to zoom out).
• Acorn will update its selection mode icons when you’ve pressed one of the modifier keys for adding, subtracting, or intersecting the selection (shift, option, shift+option).
• A new preference tab named “Mueller”. This is a little vain, but I often find myself wanting to add little tweaks just for me that I know not everyone will like. These tweaks have mostly come out of working on updates for Liquid Glass (more on that below), and I just felt like there should be a general place to do this. I know an “Appearance” tab might make more sense - but I already have ideas for other things that could go in there.
  
  Who knows (besides me of course) what else might show up there eventually, and it might even go away some day. But for now it's a place where you're going to be able to change the personality of Acorn a little bit. For now there's two options: hiding the Arial font in the font picker, and changing the app icon in the Dock.

File Compatibility

There’s now an option to save a flattened composite of each layer in .acorn files. This is a per image setting, and you can find it in the File ▸ File Info… window under “General”. When enabled Acorn will write a composite of your layer data into the saved .acorn file exactly as it’s rendered on canvas. This includes layer filters, masks, rasterized vectors, etc. This is super useful if you’d like to pull out full-fidelity representations of your layer data—something that’s super easy to do using SQLite:
select writefile('/tmp/' || layers.name || '-' || layers.uti || '.png', value) from layers, layer_attributes where layers.id = layer_attributes.id and layer_attributes.name = 'composite';

This is not currently a global setting, since it will increase the size of your .acorn images, but using the following defaults command will turn it on by default:
defaults write com.flyingmeat.Acorn8 alwaysSaveLayerComposites 1

Acorn’s file format is easy to grok and documented here: https://flyingmeat.com/acorn/docs/technotes/ACTN002.html.

I really want it to be easy for other apps to read Acorn image (even Retrobatch!). And with SQLite being the basis for Acorn image files, it's incredibly easy to get that data out.

macOS 26 Tahoe and Liquid Glass Support

Obviously I've been working on macOS 26 Tahoe support this summer for Acorn. While it was relatively easy to get something up and working with Liquid Glass, it's taking a bit more work to iron out all the details and work through OS bugs. Right now Acorn 8 supports macOS 14 Sonoma and later, so I'm not quite ready to leave those folks behind.

If the macOS 26 betas are any indication, Apple still has a lot of work left to make Tahoe amazing. I'm hoping they take their time and wait until later in the fall to ship the next great version of macOS. Acorn is going to take this approach at any rate. My goal is to make Acorn feel at home in macOS Tahoe, but still retain its own personality as well.

I work every day in macOS 26 right now, and Acorn 8.2 is fully supported even in the betas. All of Acorn's functionality is there, even if the UI isn't all glass all the time yet.