Top 4 Open-Source Alternatives to DEVONnote

Assist in organizing your piles of documents, resulting from scanners, e-mails and other sources with miminal effort.

Cryptee is a safety and privacy focused, encrypted and cross-platform personal data storage service. You can write personal documents, notes, journals, store photos and all sorts of other files.

Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.

A fork of the original Notational Velocity with some additional features and interface modifications