// Workers AI · dad joke modeWhat did TreeLine say? Branch out!
| TreeLine | |
|---|---|
| Original author | Doug Bell |
| Release | 17 October 2001 |
| Stable release | 3.2.1
/ September, 2025 |
| Written in | Python |
| Platform | Linux, Windows |
| Available in | English, French, German |
| Type | Outliner, Personal information manager, XML editor |
| License | GNU General Public License |
| Website | treeline.bellz.org |
TreeLine is a free and simple outliner with advanced data element definition and export abilities. It uses a basic tree structure to organize information, and allows the user to define different types of nodes and leaves.
File formats
[edit]Export
[edit]TreeLine outlines can be exported as HTML, per-data type user defined formatting. In addition, it supports exporting outlines as an OpenDocument ODT file, OPML, various delimited text file formats, and as "plain" XML.
Import
[edit]TreeLine can import plain text, tab indented, delimited table files, Mozilla and XBEL format bookmarks, generic XML files, ODF text documents and older TreeLine formats.
File format
[edit]TreeLine uses a simple JSON syntax to store data, with .trln extension. Versions before 3.0.0 used XML symtax with .trl extension.