elm-logo now has all the features reqired to solve the n-queens problem using this slightly modified algorithm from Rosetta Code.

to try :files :diag1 :diag2 :tried
  if :files = 0 [make "solutions :solutions+1 show :tried stop]
  localmake "safe (bitand :files :diag1 :diag2)
  until :safe = 0 [ localmake "f bitnot bitand :safe minus :safe try bitand :files :f ashift bitand :diag1 :f minus 1 (ashift bitand :diag2 :f 1)+1 fput bitnot :f :tried localmake "safe bitand :safe :safe-1 ]
end
to queens :n
  make "solutions 0
  try (lshift 1 :n)-1 minus 1 minus 1 []
  output :solutions
end
print queens 8

Open snippet in elm-logo (in elm-logo, click “Run” to run it)