Geometry Encyclopedias & Catalogues

• Encyclopedia of Triangle Centers (ETC) – Clark Kimberling
• MathWorld: Triangles – Eric Weisstein
• Catalogue of Triangle Cubics (CTC) – Bernard Gibert

Notable Contributors & Personal Sites

• Ercole Suppa (Italy) – Geometria Elementare e Problem Solving
• Francisco Javier García Capitán (Spain) – Baricentricas
• Hatzipolakis Antreas (Greece) – ΜΑΘΗΜΑΤΙΚΑ
• Jean-Louis Ayme (France) – Geometry Géométrie Geometria
• Angel Montesdeoca (Spain) – Hechos Geométricos en el Triángulo
• Quim Castellsaguer –  Todo Triángulos Web (TTW)
• Paris PamfilosGallery – Geometrikon
• Alexander Bogomolny – Cut The Knot
• Antonio Gutierrez – Geometry from the Land of the Incas
• Dick Klingens (Netherlands) – Vlakke Meetkunde
• Eckart Schmidt (Germany) – Geometrie – Themen

🔍 For an extensive list of geometry sites, visit: IMO Geometry Blog

Geometry Journals

• The American Mathematical Monthly
• ArXiv – Geometry Section
• Geometry Journal (MDPI)
• Forum Geometricorum
• Global Journal of Advanced Research on Classical and Modern Geometries
• International Journal of Computer Discovered Mathematics
• International Journal of Geometry
• Journal for Geometry and Graphics
• Journal of Classical Geometry
• Sangaku Journal of Mathematics

🔗 Master list of geometry journals: SIU Geometry Journals Directory

Forums & Communities

• Active Forums
  • Euclid
  • Geometry of Quadrilaterals & Polygons
• Archived Forums
  • Quadri-Figures-Group
  • Hyacinthos
  • Adgeom

Geometry Software

• Cabri
• GeoGebra
• Sketchpad
• Mathematica

EPG References

• Specialistic EPG References