Alexandre Stefanov long maintained a list of online math texts and other materials at Geocities, but it appears that his original web site is no longer available. Because these resources may be of interest to our readers, we present here a modified version of Stefanov's list as of November 18, 2009. We welcome corrections or suggested additions to this list.

See also Math on the Web, compiled by the American Mathematical Society, for more online math resources.

Differential Geometry

• Introduction to Tensor Calculus and Continuum Mechanics, by John H. Heinbockel
• Topics in Differential Geometry, by Peter W. Michor.
• Natural operations in differential geometry, by Ivan Kolar, Jan Slovak and Peter W. Michor
• An Introduction to Riemannian Geometry, by Sigmundur Gudmundsson, Lund University
• An Introduction to Gaussian Geometry, by Sigmundur Gudmundsson, Lund University
• Riemann Surfaces, Dynamics and Geometry, by Curtis McMullen
• Invariance Theory, the Heat Equation, and the Atiyah-Singer Index Theorem, by Peter B. Gilkey
• Differentiable Manifolds, by Mariusz Wodzicki
• Lecture notes for the course in Differential Geometry, by Sergei Yakovenko
• Differential Geometry and Physics, by Gabriel Lugo
• Differential geometry reconstructed, by Alan U. Kennington
• Course of Differential Geometry, by Ruslan Sharipov
• A Modern Course on Curves and Surfaces, by Richard S. Palais
• Undergraduate notes on Projective Geometry, Manifolds etc., by Nigel Hitchin
• Vector Bundles and an Introduction to Gauge Theory, by Steven Bradlow, (Hung-Jen Hsu and Chris Willett)
• Twistor Geometry and Gauge Theory, by Martin Wolf
• Complex Geometry of Nature and General Relativity, by Giampiero Esposito
• Projective Geometry, by Balázs Csikás
• Differential Geometry, by Balázs Csikás
• Projective and Polar Spaceas, by Peter Cameron
• Transformation groups for beginners, by S. V. Duzhin and B. D. Tcherbotarevsky
• Cartan's Corner, Differential geometry & Topology