According to a Dutch new site a KLM Boeing 737 took of from a taxiway yesterday (Wednesday) evening.
Vliegtuig steeg op vanaf taxibaan | nu.nl/algemeen | Het laatste nieuws het eerst op nu.nl
A quick and loose translation of the major part of the article.
"The aircraft was to take off from the Zwanenburg baan (36C) but took off from the parallel taxiway instead. According to air traffic control the aircraft departed without problems, but without adhering to the procedures.
All three parties involved (KLM, LVNL, Schiphol) will not comment further on the matter.
The incident was reported to the Onderzoeksraad voor Veiligheid (Investigation Board) which will investigate the incident. According to a spokesman, this is a runway incursion and it is classified as a serious incident.
The president of the Dutch ALPA, Evert van Zwol, speculates that recent snowfall might have played a roll in the incident.