TreePad ( http://www.treepad.com/ ) is a family of tree-oriented text database managers written in BorlandDelphi. Imagine notepad with the explorer folder tree glued on. Been around since 1995 or so.
Nodes can be added to the tree, copied, moved, exported, imported ...
Each node has an associated text "article" for the storage of notes or what have you.
The free version (now called TreePad Lite, ver 2.9.5) stores all its information in plain text "databases" (files) with an "hjt" extension. It uses a very simple markup internally to keep track of which nodes are the children of which parents. It features a very useful search feature.
I use it for managing ... well, a bunch of stuff, like code, configuration data, the contents of boxes packed for moving or storage, etc.
There also some commercial versions of the product that feature things like rich text editing (stored as RTF), image storage, encryption, spell checking, and so on. There is even a client-server edition (TreePad-X) which will handle absurdly large files. Hefty price tag on that one.
The developer (Henk Hagedoorn) is friendly and quite responsive. I believe the product is coded in Delphi.
Those of you who go for DoTheSimplestThingThatCouldPossiblyWork will appreciate the freeware product's implementation.
I've messed with this a bit. It's a nice idea, but I wish it used XML as its native format. -- MikeSmith
There's been some discussion on their list about that, but for the moment one uses a 3rd party tool for that conversion.
If you like the idea of Treepad, you might like jreepad (http://jreepad.sourceforge.net/). This is a java clone of treepad lite that allows you to use wiki markup to create and link articles. --PaulWright?
There is also a now murdibund OpenSource project called KeyNote (http://www.tranglos.com/free/keynote_main.html) that has a very similar set of fucntions, better in some places, not quite as good in others. It also imports and exports the PlainText FileFormat? used by TreePad. --BrianvandenBroek?
By the way, the companion or extension I'm looking forward to is an email import tool. I used InfoSelect to store email for about a year (it has an integrated email client) but found that it was ... troublesome (okay, it sucked).
The ability to organize email somewhere besides the email client's own filing system (since most of them make really awful query-able databases), and integrate that material with the other data I collect, would be a significant step up in knowledge/data/idea management. -- GarryHamilton
Vault ( http://www.personalmicrocosms.com/Vault3/WhatIsVault3.aspx ) is another nice tree editor that fits the same niche, using XML and running on Linux as well as Windows. Previously shareware, it is now open-source.