Trilium Notes

Original Feature List (with personal marked Highlights)

Notes can be arranged into arbitrarily deep tree. Single note can be placed into multiple places in the tree (see cloning)

Rich WYSIWYG note editing including e.g. tables, images and math with markdown autoformat
Support for editing notes with source code, including syntax highlighting
Fast and easy navigation between notes, full text search and note hosting

Seamless note versioning
Note attributes can be used for note organization, querying and advanced scripting
Synchronization with self-hosted sync server

Strong note encryption with per-note granularity

Relation maps and link maps for visualizing notes and their relations
Scripting – see Advanced showcases

Scales well in both usability and performance upwards of 100 000 notes
Touch optimized mobile frontend for smartphones and tablets
Night theme
Evernote and Markdown import & export
Web Clipper for easy saving of web content