It was a beneficial outliner app that improved and supported my productivity level. It has problems working with Windows 10.
Unfortunately, it's no long supported by LexisNexis.
Is there anyone familiar with Notemap who can suggest a suitable replacement for my old friend?
Thank you and it's great to be back after a few years away from this interesting site.

NoteMap's power for me were joining multiple lines of text with +m, the hoisting views, customizing the outline level, and exporting my outline to Windows Word at the push of a button.
Of course there were other features but these were the ones I frequently used.

You could try Outline 4D, though I haven't tried it on Windows 10 (it's another one of those software that haven't been updated for donkey's years).

Outline 4D works fine on Windows 10.

I used NoteMap in the days when (as far as I can remember) it was owned by its developer, before its acquisition by LexisNexis, purveyors of "legal solutions and products".

I liked it, and am sorry to see it allowed to become effectively unusable.

I use NoteMap nearly everyday with Windows 10 Pro. I am using NoteMap v 2.1 build 021. Everything seems to work fine. There were quite a few reports of some bug in longer outlines that caused a loss of data but it never happened to me. I use Checkvist and Dynalist online, but I have yet to find a better desktop product. I use OutlineEdit and OmniOutliner on Mac but none of them feel quite like NoteMap. All have their good and bad points but NoteMap is still my go to outliner. For now... JT