Strange Question About Previously Published Material

There's a small forum I'm involved with and week before last, I wrote a small story for a writer's block challenge which won the contest. I'm thinking this story might be good to revamp and submit to markets. However, I'm a little confused as to what might be considered previously published since this piece is posted on a forum. (?)

Also, the challenge was to write a fairytale or nursery rhyme from a completely different perspective. So I wrote a spin from a famous nursery rhyme, like telling the real life version of what happened. What genre would that fit under?

Thanks a ton in advance, guys and gals.

Wow. I'm used to replies within mere minutes. Have I finally stumped the forum?

There was no expressed rights for it. Just a bunch of writers challenging ourselves. It was a spur of the moment thing and I wrote it not even thinking about the publishing aspect. It's a good piece though and I'd like to be able to market it now. I guess I could try to see if they'll remove it but since it was the winner, I don't know if they'll be too thrilled about it.