Available for free.
In one-pane outliner, all parts of the document (either categories or category content) are displayed in the same area.
Moreover in outliner with a single pane any part of a document can be a category and a content at the same time.
When all your data is in one pane, it is very easy to "play" with content: to move rows up or down, indent or unindent them, create or reorganize structure of a document.
Multiline Rich Text
Each row in the outline can have multiple lines of a rich text. This means that you can format rows in the outline like in any word processor – you can specify colors, font sizes, etc.
Your outline document can contain columns. Each column supports rich text as well.
Styles in UV Outliner allow you to specify, how to format rows in certain hierarchies. Automatic styling also helps you format the document uniformly while typing.
Your outline can be exported to plain text or HTML.
UV Outliner supports printing of the outline. If checkboxes are enabled they will be printed as well.