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Opal is an outliner. It lets you organize just about anything - ideas, reports, lists, notes, projects, graphics - as an outline. It stands out for its uncluttered, fluid interface. But Opal includes features not found in other organizers:
  • Shrink a topic to a single line
  • Alphabetic and numeric sorting
  • Magnify on-screen text
  • Word count
  • Focus on part of the outline
  • Multiple selection
  • Link to other documents
  • Just create notes - no need to name them
  • Open Acta outlines
  • Spotlight search
  • Topic filtering via toolbar Search field
  • Smart checkboxes more...

What's New

Version 1.2.5:
  • This version requires Mac OS X 10.5 (Leopard).
  • Fixed some memory leaks.
  • Quit faster under Snow Leopard (10.6).
  • Fixed an OPML bug.
  • Added link to Facebook page.


Mac OS X 10.5 or later

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Opal User Discussion

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Squidbot Member IconReview+2

I use this app almost every day. It's a great tool for doing "brain dumps" for software design, basically I use it as a mind mapping tool without all the graphical clutter. It's also great for taking notes in meetings.

Reply0 replies
Version 1.2.5
P. Maxwell Member IconReview+11
P. Maxwell

I've been using Opal 1.2.2 for the last few days.
I find this program very comfortable to use - it is easy to make it fit my needs and the way I work. For instance, I can easily enlarge the size of the text on my screen without changing font size. I can give alternating lines a different colour of my choice to easily differentiate and enclose lines of text.
It is obvious that the creators of Opal have put a lot of thought and experience into making this program. They seem to know what a user like myself needs.
I had occasion to contact the programers - on a Sunday! - and was quite astonished to have almost immediate responses that were both succinct and helpful.
The help section is excellent. One thing that puzzled me, though, was that the part about preferences says that you can set a preference to allow you to give any menu item whatever keyboard combination you want. I couldn't find this in the preferences but would love to have it in the future. Or maybe someone could tell me how to do this in case I have just missed something.
Another thing I would like to see would be a highlighter feature with a button on the toolbar - such as in Scrivener or DevonThink, among others. There is a workaround possible in Opal by using copy and past style, but this isn't quite as convenient as a dedicated highlighter.
Personally, I am very grateful for Opal and look forward to using it for some intensive and constructive outlining - as I used to do with ACTA.

Reply3 replies
Version 1.2.2

Re short cuts: For all OS X apps you can go to System Preferences > Keyboard & Mouse > Keyboard Shortcuts and set shortcut keys either for individual apps or globally.


@LEV: Perhaps the solution you mentioned here requires a specific minimum version of OS X? I tried it on 10.4.11, and it didn't seem to work. I couldn't find any application specific settings for Opal, nor could I find any applicable universal settings. The built-in shortcuts for indent and outdent definitely aren't ideal for my fingers... would love to adjust this, since it's a great app.


Sorry -- I had given up prematurely. I have now figured out how to do it using the "+" button to add a new shortcut. I still couldn't find away to make the tab key work for indenting and outdenting, but I was able to input a workable alternative. Thanks for the tip.

blloyd Member IconComment+216

Whatever this 1.2 download is, it's corrupted.

It downloads a .bz2 compressed file, and if you extract that you get a .bz2.cpgz file. If you extract that, you get a .bz2 file again.

The only way I can get it to extract is to use BetterZip and extra the package, as the default BOMArchiveHelper app won't do it.

So you get an Opal 1.2 DMG file, which when double clicked notes "no mountable file systems."


This isn't an issue with MacUpdate per se, as the downloads from the developer site (and their mirror) exhibit similar behavior.

Perhaps they should try a better packaging mechanism next time. I've used .bz2 archives before and they've worked (LaunchBar is compressed this way), though frankly straight .dmg files are nicer, and they can compress as well. Maybe not *quite* as well as .bz2, but 2.6 MB versus 5 MB for a download these days is pretty trivial.

Reply5 replies
Version 1.2

Download the file. Remove the .bz2 suffix. Resulting .dmg will mount.

A Sharp, Llc (Developer)

This is covered in our FAQ . Rename the file to ".dmg".

Since we only post .dmg files, I would love to know who is changing them to .dmg.bz2 -- I always test both download links before going public, and they always work for me.


The ".dmg.bz2" issue is fairly well known:


A google search using the criteria .dmg.bz2 gives more info.

A Sharp, Llc (Developer)

Thanks, I set that up on our server. I couldn't reproduce the bug though, so I don't know if it fixes things.


Well, for what it's worth, I just now downloaded Opal 1.2 using Safari 3.1.1 (4525.18) on OS X 10.4.11 from my home here in Mexico (TelMex broadband service) and the .dmg appeared on my desktop as "Opal-1.2.dmg" and the image mounted with no issues.

funjoy Member IconReview+104

Basic outlining par excellence.

Reply0 replies
Version 1.1.1
Nydhogg Member IconReview+1

Except now it's called Opal. The classic early Macintosh outliner ACTA has been brought up to date without adding the bloat found in other outliners, but still adding a great new search feature and multiple topic selection, a very handy feature.

The property of selecting a topic with a single click and opening it with a double click (carried over from ACTA) is a particularly big winner - I can't stand outliners that open a topic with a single click - what, do these people never reorganize their outlines?!

It opens all my old ACTA outlines and runs as a Universal App providing a great bridge to the latest Macs.

Kudos to David Dunham and A-Sharp - Web Heroes in my book!


PS: I was a beta tester, but I have no financial interest in the product.

Reply0 replies
Version 1.0.6
Sandy-C Member IconComment+1

Can't mount the 1.0.2 disk image under 10.4.8 using either the OS or Toast to mount it.

Reply3 replies
Version 1.0.2
A Sharp, Llc (Developer)

Please use our support system -- we can give you much faster support.

I think the answer may be in our FAQ. Chances are the .dmg file somehow got named .dmg.bz2. If so, just remove the ".bz2" portion of the extension and try again.

If neither that nor the other possibilities in the FAQ help, contact us (bugz _at_ a-sharp _dot_ com).


Thanks. That did it.

A Sharp, Llc (Developer)

Also, I just reconfigured our server. One user who reported the ".bz" issue says it now works like it does for most people.

WhoCares742 Member IconComment+3

This is a "free preview." In other words once it is out of beta it will no longer be free. The price - "We don't know yet"

Reply1 reply
Version 1.0b1

MacUpdate changed the description from free to demo. Thanks for the correction.

tomstraus Member IconReview+9

Opal, an OS X update to Acta, has some nice additional features and works as expected. Import of OPML permits translation of a number of other formats to Opal. It doesn't have the extensive feature set of OmniOutliner or TAO, but then, some of us taking notes just want something simple and easy that works fast. Opal does this.

Reply0 replies
Version 1.0a5
ncianca Member IconComment+23

Thanks! I lived on Acta for a long, long time. It's nice to see it come back and have a way to open up some of those old files.

Reply0 replies
Version 1.0a4
davermont Member IconComment+8

I used (and loved) Acta for years on pre-OSX Macs and still have many dozens of outlines in Acta format. Thanks, A Sharp, for creating an OSX version of that wonderful app!

Reply0 replies
Version 1.0a1
There are no Ratings for this App yet.
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Current Version (1.x)


Downloads 16,412
Version Downloads 3,787
License Shareware
Date 14 Oct 2009
Platform OS X / PPC 32 / Intel 32
Price $32.00
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