OutWiker is a cross-platform software for keeping your notes in a tree. Similar programs call "outliner", "tree-like editor" or personal wiki. Main difference OutWiker from other programs is a keeping notes as folders on disk. A notes can to have attached files. OutWiker can contain pages of different types, currently supports three types of pages: plain text, HTML pages and wiki pages. OutWiker uses some sets of free icons taken from sites famfamfam.com, yusukekamiyamane.com and fatcow.com. Many thanks to the authors of those sites.