Free non-commercial giveaway philosophy. The word is based on the world-famous internet band Lagoona from Sweden, who got several hit songs on the MP3 charts (including two #1 tracks on MP3.com) during the years 1997-2003. Lagoona gave away the music for free, and claimed that "giving away music for free makes us happier than if we'd keep it until a label released the material". With 7,000,000 million Lagoona songs downloads during the eight years the band existed, that philosophy got wide-spread.
Goonish material started popping up at many other places than in the internet music scene, and as of today, the word is widely used - especially in the northern parts of Europe. The term "goonware" has also been used in speech, and advertising sites have often had goonish classifieds, with statements like "Given away in the goonish spirit".
Due to the non-commercial nature, there can not be any form of goonish TV-commercials or sales advertisements.
"This is goonish stuff" means "This is free stuff that the creator wants us to have - with no commercial interest".
"Goonish file:" means "free-to-download files".