is "Gb" gigabyte or gigabit?

I sometimes get errors of this form:

Error: cannot allocate vector of size 13.8 Gb


I've also seen "Gb" used in R documents.  Is "Gb" being used to refer to 
gigabyte?  We usually refer to bytes and gigabytes when discussing memory 
usage, but the lowercase "b" more often refers to bits.  According to 
Wikipedia:

   http://en.wikipedia.org/wiki/Gigabyte

   "The unit symbol for the gigabyte is GB or Gbyte, but not Gb (lower
   case b) which is typically used for the gigabit."

If "Gb" means gigabyte in R, I can live with that, but I think it is 
ambiguous and confusing.  If it does mean gigabit, I think we should refer 
to gigabytes instead when discussing memory usage.

Mike