bug#31065: relationship with Zlib? Re: bug#31065: Version 2??

[Garreau\, Alexandre]

Sorry, in my excitement, I sent my last mail without looking at what I
wanted to say/ask in my first draft:

I’m not sure of recalling or understanding fully, but isn’t pigz
somewhat linked with Zlib/Zlib code? and Zlib not being GNU, what would
that mean? would it have to be separated? would gzip get Zlib as a
mandatory dependency? How would that evolve?

As I understood anyway you Mark Adler the maintainer of Zlib are anyway
quite active on these mailing-lists.  Out of curiosity, and I’m probably
bad at formulating it at a quick glance but I’m not sure of what are the
relationships and differences between zlib and the (redundant?
different? independant?)  standalone compression tools it reimplements
(or the other way around?), including gzip, especially when some people
working on all these are the same: then there must be some relevant
useful difference that justify the differenciation of both?

I first learnt about pigz on a (french) (micro)blogger website [1], then
I was really curious about why a such useful and uncontroversial change
wouldn’t go upstream (as afaik stuff not going upstream for gcc or glibc
has been common for several times in their history), not only for gzip
but also for lzip, xz, bzip2, etc.

Thank you in advance for any answer!

[1] fr: <http://sebsauvage.net/links/?DrNtGw>