In my opinion, some of the commenters here are missing a key point: CP NoteBook's primary strength was its extremely robust handling of outline-structured data. On top of that its "multidex" allowed viewing outline data in various other ways.

Various software packages support creating a simple outline for a simple purpose; e.g., spec'ing out the structure of a document prior to writing it. But outlines are ideal for something far bigger: handling and integration of all the information, action items, and projects someone with a non-routine job (or life) deals with. I update and reference the outlines I use to "run my life" continuously during the day. There have only been a handful of software titles I've found over time that have been able to support that. Starting from "the beginning": ThinkTank, More, Grandview, Noteliner, CP NoteBook, (NOT OneNote), and now out of necessity I've switched to OmniOutliner. Omni supports the kind of industrial-strength outlining that CP NoteBook did, although it lacks the multidex feature, which I used principally as a way of managing my to-do's without having to manage a separate to-do list.

CP NoteBook's ability to support attachments, tables, free-form notes, etc was all gravy--there are plenty of other options for handling those. Its truly important (and sadly under-appreciated) capability was its industrial-strength outlining.

No doubt Circus Ponies is a very good outliner and very good piece of software -- it fell on hard times, and now, lamentably, it is exiting the stage for reasons only the owner knows for sure. So, most of the discussion here has been reaction to that situation, and, more importantly, what to do next.

Understood. I think there are a number of alternatives available for many of its "peripheral" capabilities. But for the industrial-strength outlining functionality at its core, the only serious substitute I've been able to find is OmniOutliner.

An app that could have had the potential to replace Circus Ponies Notebook's outlining capability was Note Suite, which sadly has also gone belly up. But I found it an excellent outliner. Similar in some ways to CPN. It also had the ability to manage tasks. In fact -- just in my view -- it was a more nimble outliner. And it had an excellent iOS companion app. Not sure why I'm bringing this up, other than to whine about another lost piece of software.

Steve Z.

Given their mortality rate, remind me never to write an outliner product...

I've sometimes thought of writing my own just so I wouldn't have to worry about it going away!

Bob Spies wrote:

I've sometimes thought of writing my own just so I wouldn't have to
worry about it going away!

You would have to keep updating it just to keep it working on that latest OS. Especially for Mac, as Apple like to nuke their development ecosystem from orbit every few years.

I am not sure I share the same sense of nostalgia given that some really powerful contenders are with us right now. Will they only be remembered when they have drop out of business?

1) Neo, ridiculously powerful, accessible, cheap http://d-lit.com/macosx/neo_outliner/ alas, Mac only - I have it open now and should be working

2) Tinderbox, harder to grasp, much more expensive but has some nice tricks up its sleeve. I'll leave them to Steve Z to explain :-)

and of course

3) org mode , free, endlessly hackable. It is sometimes said that it is not for the faint-hearted, which I find inaccurate because the core functionality is not excessively hard to grasp. It is not for the easily distracted, though. orgmode requires consulting forums, manuals etc because none of it follows any kind of standard for any operating system that have all evolved long after emacs, the foundation on which orgmode is built, had been devised. It is really easy to veer off into a thick undergrowth of trying to define a function once you learn that in the dot file functions can be defined when yaddayadda....and completely lose sight of the small problem you wanted to solve.
If you have the mental strength to ignore 97% of excess functionality that was really designed to do something you don't need and resist even finding out what its purpose is then orgmode might be all you need.
Else: 1 or 2

But doom and gloom? Not really.

I've looked at Tinderbox. Innovative, but not really what I need for day-to-day info & project management.

From time-to-time I consider trying org mode, but I'd need to leave the real world for a week to try and get it working for me--haven't found the time for that yet.

Neo looks intriguing. Somehow I've managed to miss it until now. Any idea what kind of staying power it has?

Bob Spies wrote:

From time-to-time I consider trying org mode, but I'd need to leave the
real world for a week to try and get it working for me--haven't found
the time for that yet.

Totally understand. It took me several attempts to finally get going, what really made a difference was identifying an emacs variant that looked nice and at least conformed to some standards of my operating system to ease the transition. In my case spacemacs, but your mileage may vary.

Neo looks intriguing. Somehow I've managed to miss it until now. Any
idea what kind of staying power it has?

I do not have any first hand knowledge but the developer seems to be very devoted to his quest. Neo has been around for a long time and its predecessor TAO before it. Neo gets regular updates especially after new OS X releases. If you are looking for something less puzzling (if not downright weird at times) than both Tinderbox or orgmode then you cannot go wrong with Neo, especially at the price. Stable as a rock and very powerful (hoisting, true cloning, even graphical representation of links that you define, etc). The manual is quite helpful BTW and can be downloaded in Neo format from the developer's website.
I tend to do project-related note-taking in Neo often and really like it in case you haven't noticed.
Spend some time configuring it, especially the keystrokes, and you are unlikely to hit any major obstacles, whereas both Tinderbox and orgmode, as much as I like them, require some thinking ahead to avoid the "it is probably easy but I'll be damned if I know how I can make this thing do XYZ" syndrome.

Hope this helps
Prion

Wow, that sounds great. I'm pretty happy with OmniOutliner at the moment, but as soon as I have a bit of time to spare I'll give Neo a try.

Thanks!