Tree, Horizontally expanding outliner.

Tree is an outliner featuring a horizontally expandable tree view.

Tree assists you in organizing your information, sketching plans and brainstorming new ideas. Tree allows you to store your ideas and keywords in segments that you can sort, re-arrange and constantly refine. Tree is designed to be a lightweight application that lets you concentrate on your ideas.

Download on the Mac App Store

Tree view

In tree view, Tree displays your data in a horizontally expandable tree diagram. This offers you a more intuitive way of working with your outlines. You can easily switch between tree view and a traditional list view while editing your documents.

Tree view List view

Examples of usage

Tree can be used for

Tab Bar *

Newly added button on the far right of the tab bar. Click this button after selecting an item. The content of the item is then displayed in a new tab that just appeared, so you can focus on an interesting part without distraction.

* In Tree 2, the tab’s function changed to focus on showing items in separate tabs. Accordingly, the capability to edit multiple documents in one window is removed.

Plain Text and Rich Text

Tree now supports a new file type to handle rich text with the ability to choose from multiple fonts and styles ( bold, underline, italic ). If, for example, you want to print text in monochrome or need to use a foreign language font for some words, you can change font and style for each word.

You can select the document text format from the format menu or change the new document text format in the preferences.

Input and Output

Tree can open Plain Text (.txt), Rich Text (.rtf) and OPML 1.0, a XML format for outliners.

Tree documents are stored in a native format and can be exported as Plain Text, Rich Text, Word 2007 Format (.docx) and OPML 1.0 documents.

And now it is also possible to directly export a document as a PDF file without the help of the print panel, via the newly added "Save as PDF..." menu item in the "File" menu.

Checkbox, Note, Numbering and Color Label

Checkboxes to keep track of to-do lists, Notes to add information to items and Labels for color coding.

Tab Numbering

"Spelling and Grammar" and "Substitutions" *

With "Spelling and Grammar" you can check spelling via the spell check service provided in OS X. To use this feature, choose the menu "Edit" > "Spelling and Grammar" > "Show Spelling and Grammar" to show the "Spelling and Grammar" panel. This panel allows you to find and correct misspellings. With "Substitutions" you can, for example, automatically convert your typed URL text to a link by turning on "Smart Links". Also, if you would like to convert all URL text in your document to links,

  1. Select "Edit" > "Substitutions" > "Show Substitutions"
  2. Select the "Smart Links" check box in the Substitutions panel
  3. Click "Replace All"

Now all recognized URLs are converted to links.

If plain text is selected, just turning on "Smart Links" will convert all detected URLs to links.

* To use these features, please click the selected item and make sure you can edit its text.


You can change the behavior of basic keys (return-key/delete-key/tab-key) in the Preferences. Tree is designed to be a lightweight application that lets you concentrate on your ideas.

Created for Mac

Tree supports OS X’s Versions, Auto Save, Resume and Full Screen.


Download on the Mac App Store

You can use it instantly after downloading.


Download on the Mac App Store


Trial / Direct Download Version

Ver.2.0.3 - 2/25/2015 - 3.1MB - CRC32:$5B07DFCB

Req: Mac OS X 10.9 or later / El Capitan Ready

- Latest Software Update is recommended. -