MenuBrain is described as 'is the info organizer I wanted someone else to make. It’s stupidly simple'. There are more than 25 alternatives to MenuBrain for a variety of platforms, including Mac, Windows, iPad, iPhone and Linux. The best alternative is Simplenote, which is both free and Open Source. Other great apps like MenuBrain are Notational Velocity (Free, Open Source), BasKet (Free, Open Source), UpNote (Freemium) and Quiver (Paid).
Notational Velocity is a mouseless application for storing and retrieving notes. With Notational Velocity, searching for notes is not a separate action; rather, it is the primary interface. Searching encompasses all notes content and occurs instantly with each key pressed.
Quiver is a notebook built for programmers. It lets you easily mix text, code and Markdown within one note, edit code with an awesome code editor, live preview Markdown and LaTeX cells, and find any note instantly via the full-text search.
recordando (Spanish for remembering) is a program in which to keep your written thoughts This space has these characteristics: It presents a simple organization on screen (like post-it notes) It's safe and secure; it runs on your own computer and not on the Internet ...
NoteAway is the simplest, most convenient way to take quick notes on OS X. NoteAway has lots of powerful features for free, like iCloud syncing, rich text, attachments, simple import/export, and a variety of customizable options.