Keynote-NF development has continued and the last beta release was in January.

http://code.google.com/p/keynote-nf/
http://code.google.com/p/keynote-nf/downloads/detail?name=Release_1.7.9.3 Beta 4.rar

Developer says:
"I'm working in a totally new application, based in .NET and db4o object oriented database. My intention is to add to this new application basically the same functionality of today's KeyNote and all that things that I'm really interested in. I have a very clear idea of what I want and there are many things that are very more difficult to implement in current KeyNote. This new application will be open source too. Soon I will create a new project in Google Code for that new application."

might be interesting to some here.

It does not follow the fashion - and new trends - of Software as a Service, web-based apps, or the current hype around AI integration.
Instead, it remains an old-style knowledge-management outliner for Windows. It is free and, unusually and to its credit, still under development.

The good news is that it runs - and very fast - using about 5 MB of RAM and fits into a portable folder of roughly 10 MB.

One of the first things I test in an outliner is drag-and-drop in the navigation pane, and here it works perfectly. It accepts RTF formats and supports OLE objects (including, as I tested, my installed MS Equation Editor).

In the mortuary cemetery of classic outliners, this one feels unexpectedly alive. I have no affiliation with the project, but I’m glad - and surprised - to see it still going.

https://github.com/dpradov/keynote-nf

The commercial software RightNote was, I believe, inspired by Keynote NF. It's a pretty good outliner, with some really useful tagging features.

James Salla wrote:

RightNote was, I believe, inspired by Keynote

Good spot: they share in fact the same classic outliner philosophy - one of the majour causes of CRIMP desease, I believe. RightNote has admittedly added several additional features; however, in my testing it is not as crisp or responsive as KeyNote. For instance, it requires at least 150 MB of RAM and nearly ten times more disk space (around 90 MB).

Moreover, OLE objects - which allow embedding and opening other document types within the outliner - have proven more reliable in KeyNote NF based on my limited experience.

"The good news is that it runs - and very fast - using about 5 MB of RAM and fits into a portable folder of roughly 10 MB."

Is this the case even when it has a significant amount of information stored in it?

I am not a regular Keynote NF user, so others in this forum may be able to provide more accurate insights. I still use the classic MyBase 5.1.1, which was considered an “advanced” outliner in the early 2000s. Keynote NF, however, appears to be in the same league, and I was pleasantly surprised to find that it is free and still actively developed — including a 64‑bit version with UTF‑8 support.

For what it’s worth, here is my brief experience with the 64‑bit portable edition on Windows 10:

- With a new outliner file containing only a few notes: RAM usage ≈ 5 MB
- With the included help file (slightly over 1 MB in size, about 130 notes containing text and images): RAM usage ≈ 10 MB
- After some editing and expanding all notes of the help file: RAM usage ≈ 15 MB

These values seem quite low, especially considering that this is a 64‑bit version, which typically consumes more memory than a 32‑bit build. The trend is clear and predictable: RAM usage increases as the file grows. Much more testing and long‑term use would be required to make a definitive assessment.

That said, I often judge software performance from its responsiveness at first launch, and Keynote NF gives a very good impression (if one is still found of the "classic" outliners). Often, from this initial feel, I often even try to guess the underlying quality of the codebase, and type of programming language used.

Nomatica wrote:

Is this the case [low RAM needed] even when it has a significant amount of information
stored in it?

While browsing the help file, I found this feature, which partly addresses the question.

Storage of images - option: "External: Images are not located in .knt file, but in external files, on a external folder or inside a Zip archive."

If I understood it correctly, this keeps the file format ".knt" of Keynote relatively lightweight, and reactive, even with many notes.