For sometime now that I've been hunting down for such software. I've found a few open source applications, that I started testing today... and have started with CherryTree. Below, you can find the list I gathered. It may be useful to others. The Guide -http://theguide.sourceforge.net/ wikidPad -http://wikidpad.sourceforge.net/ Tobu -http://tobu.lightbird.net/ KeyNote NF -https://code.google.com/p/keynote-nf/ Zim -http://www.zim-wiki.org/ NeverNote -http://nevernote.sourceforge.net/ RedNotebook -http://rednotebook.sourceforge.net/ KeepNote -http://rasm.ods.org/keepnote/ cherrytree -http://www.giuspen.com/cherrytree/ I like these kind of software to help me writing notes, for my studies, in a hierarchical structure. It keeps things very clean. The hard part is: Which one to take? Overall, they all have their uses. They all share the same basic uses. They all have their pros and cons, as any other software does. I'm testing CherryTree right now, and it does what I want - hierarchical notes; it allows to insert images, text style... Why does it have to be this complicated to choose one? I'm wondering if any one has ever come across any of these I mention here and what's been your experience over time?