NeoFur - Fur, Fibers, Fuzzy Surfaces and more!

I have a “legal” question…
I once buy the indie licence and now, they gave me (and to all buyer) the sources of the plugins.
I do my own maintenance on it and maybe, some people in the same situation will upgrade it, add new function, correct some bug…
Can we share this work ? With who ?
Who is the legal proprietary of the code ? I know that it is not a free code but it’s not for sell any more and we have no clue about the new owner identity, do we ?
How can we add it to the credit of a game made with it ? By naming “neoglyphic” (witch doesn’t exist ?) ? Or the new owner (witch I don’t the name) ?

What can we do with the plugin ? What can’t we do ?
Is it just a ghost code, lost forever for every one that didn’t buy it at the good time ?
What does neoglyphic means by releasing the source code to licencies ?