vimwiki plugin for vim
With vimwiki plugin it's simple to maintain wiki-like knowledge base or diary. It allows you to organize notes and ideas, manage todo-lists, write documentation and more.
Zim is a desktop note taking app that allows the user to form wiki like structure with the notes contained within. A Windows and Linux client are available.
Workflowy is a text based to do list that focuses on using bullet points to mimic naturally occurring thought patterns, much like a mind map.