Main page of BERLiNiB:

As good as 
Adobe PDF Reader 
when you use Linux

Adobe PDF Reader 
is available for 
all commercial 
platforms, including
all phone types, 
see links on top 
of main berlinib 
website.
On Linux, there are 
numerous alternatives to
Adobe PDF Reader, and
these work for all
standard PDF format
although some late
additions to the PDF
standard may require
Adobe's own reader. 
If you are using Linux 
and there is a 
compatibility need for
a particular Adobe 
version, you can go to 
such as askubuntu dot com
to search up how you 
install Adobe under Wine,
allowing Adobe's own
readers to work in Linux.

Though the links on top 
of the berlinib website
mention 'linux', Linux 
has its own PDF reader
alternatives. A full Linux 
usually has one
already installed. 
At any up-to-date Linux 
related eg to Ubuntu, 
such as KDE Neon, you 
can install a good PDF 
reader like 'evince' 
or 'okular' by open 
the program called Terminal
and in it write either
  sudo apt install evince
or
  sudo apt install okular
and answer the normal 
questions it asks. 
At Fedora, there are
similar instructions;
and there are many more
PDF readers available
at Linux.
Evince is elegant, fast,
and allows effortless 
copying of text. 
Once you have decided 
on which PDF reader to 
use, eg, evince, you can 
set your browser to use 
it. In Firefox or Seamonkey
or related products, this is
usually the way: under 
"General", scroll to 
"Applications". 
In that list, find 
"Portable Document Format" 
and click to the right 
of it, select "Use other",
and type in the 
name of the program 
with /usr/bin in front, 
eg /usr/bin/evince 
(or /usr/bin/okular).
If this doesn't work,
open a terminal and type 
whereis evince
and it will tell you.