QOwnNotes!

Notepad++ is a free source code editor and Notepad replacement that supports several languages.

Made by the company behind WordPress , Simplenote is an easy way to keep notes, lists, ideas, and more. Your notes stay updated across all your devices. No buttons to press. It just works. Your notes are synced across your devices when you create, add to or change them.

A hierarchical note taking application, featuring rich text and syntax highlighting, storing data in a single xml or sqlite file.

TagSpaces is an open source personal data manager.It helps you organize and browse your files on every platform.

Have you ever felt the frustration at not being able to locate a website you wanted to check out, or find an email you found interesting, or remember an idea about the direction of the political landscape in post-industrial Australia? Or are you one of those desperate souls with home-made, buggy, or not-quite-perfect notes systems?

Love Notes. Love Encryption.

Take quick notes on Post-It(r) like sticky notes on Windows desktop, stick those notes to websites, documents & folders. Set reminder alarm to each sticky note. To avoid desktop clutter, you can organize those sticky notes inside folders. Send sticky notes to another computer over local network (LAN) or Internet, Sync sticky notes between computers using the Notezilla.Net cloud service, access your sticky notes on any smart-device such as iOS(iPhone/iPad), Android, Windows Phone, Blackberry etc. »

Leanote provides services for note and blog. You can use "note" as your personal notebook, if you want to share with friends, just publish note or notebook to the blog.

NixNote, formerly Nevernote, is an open source client for Evernote . It is written in Java so it will also run on Windows & OS-X, but the primary focus has been to try and get a usable environment for Linux.

nvALT is a fork of the original Notational Velocity with some additional features and interface modifications by Brett Terpstra and ElasticThreads.

Very similar to Notational Velocity but for Windows.

Gorgeous note-taking app for Mac with Evernote integration. Alternote has pixel-perfect interface, robust search, distraction-free mode and lots more. It is designed to be the most convenient and natural way to make notes, collect information, write down your ideas, feelings and memories