The HG&OG Tool (Horrendograms & Organigrams) is an advanced interactive knowledge graph platform developed by LifeWatch ERIC in 2025. Its main goal is to connect European legislation, organizations, and MARBEFES BBTs (Broad Biogeographical Typologies) within a unified, dynamic and visual system.

The tool combines the structural logic of organigrams (institutional hierarchies and relationships among agencies, departments, and ministries) with the relational complexity of horrendograms (multilayered conceptual maps). This dual representation allows users to explore how legislation, policies, executive agencies, and sectors interconnect across spatial (location-based) and administrative (umbrella and policy-based) layers.

Built as a web-based visualization engine, HG&OG offers full graph navigation and interaction: users can drag and reorganize nodes, double-click to view detailed information, and filter by categories such as Location, Umbrella, Executive Agency, Sector, Policy, and Legislation. The system integrates a distance filter (1–3 hops from any node) to control the complexity of the displayed network and focus on relevant relationships.

The platform functions similarly to Obsidian’s graph view, offering a semantic navigation experience through interconnected data layers. This makes it especially useful for exploring policy relationships, institutional dependencies, and the connections between governance frameworks and MARBEFES BBTs.

HG&OG is part of the LifeWatch ERIC knowledge infrastructure, supporting policy advisors, environmental researchers, and ecosystem managers in understanding how governance systems influence biodiversity-related domains. The application uses graph-based storage and visualization frameworks, integrating both manually curated and automatically extracted metadata from European institutional and legislative datasets.