Theo van Doesburg (1883-1931)

Painter, poet and art critic who established the De Stijl magazine, from which the Movement took it's name.

The magazine ran 1917-32.
guggenheimcollection.org/site/artist_bio_157.html

Piet Mondrian (1872-1944) also spelled Piet Mondriaan

One of the main founders of the De Stijl Movement. He called his style Neo-Plasticism. He was the long-term purist of the movement, although even he finally broke the formula after moving to New York and developing a taste for jazz. He went to the extreme of making paintings WITHOUT black lines *gasp* such as the famous "Broadway Boogie-Woogie": webexhibits.org/colorart/mondrian2.html
ibiblio.org/wm/paint/auth/mondrian
artchive.com/artchive/M/mondrian.html
guggenheimcollection.org/site/artist_bio_112.html
This is fun: www.ptank.com/mondrian

J.J.P. (Pieter or Pietr) Oud (1890 -1963)

Jacobus Johannes Pieter Oud, architect and one of the founding members of the De Stijl movement. He left the group due to philosophical differences and went on to become one of Holland's premier Modernist architects.
greatbuildings.com/architects/J._J._P._Oud.html

Gerrit Rietveld (1888 ­ 1964)

Furniture designer Rietveld produced the famous Red & Blue Chair in 1918. The De Stijl founders were so impressed by this piece that they invited him to join them, and became the foundation for their distinctive designs.
centraalmuseum.nl/rietveld/index.php?lingo=UK
greatbuildings.com/buildings/Schroder_House.html
cassinausa.com/rietveld.html
roland-collection.com/rolandcollection/section/34/502B.htm
r20thcentury.com/bios/designer.cfm?article_id=85
modernclassics.com/rietveld.htm
galinsky.com/buildings/schroder

Italian Futurism

Futurism may look a lot like other European Modernist Movements but there's a darker side. The Manifestos on which the movement is based are often violent, intense and anti-social. Exponents came from both extremes of the political spectrum - fascists and revolutionary leftists.Google.com image search for Futurism
Google Directory - Art Movements - Futurism
artchive.com/artchive/futurism.html

FT Marinetti wrote the first Futurist Manifesto in 1909.
futurism.org.uk/marinetti/mar_frames.htm
unknown.nu/futurism

Umberto Boccioni was one of the prime artists of the Italian Futurist movement.
artchive.com/artchive/B/boccioni.html

The predominant form of Applied Art / Design undertaken by the Futurists was architecture. Antonio Sant'Elia even wrote a manifesto about it. My, those Futurists were a bunch of angry young men. They mostly died in WWI, somewhat ironically killed by the very machines, violence and anarchy they so glorified.
futurism.org.uk/architecture/architecture.htm
unknown.nu/futurism/architecture.html

Another Futurist Architect was Nicolay Diulgheroff who designed the very Art-Deco looking Mazzotti House. Unfortunately, the best website featuring this house is in Italian. Considering that the house is in Italy, I guess that's no great surprise. www.tulliodalbisola.it/casa_mazzotti You can try a pretty bad automatic English translation.