Trilium Notes (TriliumNext / Trilium) is an open-source, cross-platform note taking application designed to help users build and maintain a personal knowledge base. It allows organizing notes in a tree structure, supports deep hierarchies, note cloning, rich editors (with tables, images, math, code syntax highlighting), full-text search, note versioning, and attribute-based querying and scripting. It also includes features for synchronization via a self-hosted server, per-note encryption, sharing notes publicly, and tools such as relation-maps/mind-maps to visualize connections among notes.