What online puzzle competitions are there for advanced solvers?

competition/contests/online.competitions New

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Problem

What online puzzle competitions are there for advanced solvers?

[ Editor: problem statement reconstructed from the postings. ]

Show solution

There are several online puzzle competitions catering to reasonably
advanced puzzle solvers.  None have prizes.

For example,

PQRST - run by Cihan Altay

Forsmarts - run by Vladimir Portugalov

IPST (Internet Puzzle Solvers Test) - run by the Russian puzzle club
Diogen

WPC (World Puzzle Championship) - run by the World Puzzle Federation

PDT (Puzzle Design Tournament) - run by Cihan Altay

Turkzeka - run by Yilmaz Ekici

-- rec-puzzles.org wiki contributor (203.213.7.133)