5 links
Mondrian Trust
mondriantrust.com
The official site of the Mondrian/Holtzman Estate. Copyright information, artist's works and biography.
Stephen Linhart - Mondrimat
stephen.com
A simple system that experiments with space, color and visual rhythm in accordance with the theories of Piet Mondrian.
Stichting Mondriaanhuis
mondriaanhuis.nl
The Mondriaanhuis foundation is housed in the birthplace of the painter, his biography, exhibitions, and links.
WebMuseum - Mondrian, Piet
ibiblio.org
Contains a few paintings, and an article about pure abstraction.