Question about fanfics

[dzny72]

I just read the posts on reviewing fanfics, and I decided that I 
finally needed the answers to a few questions.  I just recently began 
reading fanfics, just b/c I can's stand the wait until HBP.  Anyway, as 
I am going through trying to decide which ones to read, I am coming 
across a "code", so to speak, and I am not sure where to look for a  
translation.  What does AU mean? And what is a WIP?  And what 
is "slash"?  If anyone can help, I would greatly appreciate it.  Also, 
if there are any other of these types of abbreviations that I did not 
list, the answers would be great, b/c I am sure I will come across them 
sooner or later.

Thanks!!