This is Perl module Plack::Middleware::ServerName.

INSTALLATION

Plack::Middleware::ServerName installation is straightforward. If your CPAN shell is set up,
you should just be able to do

    % cpan Plack::Middleware::ServerName

Download it, unpack it, then build it as per the usual:

    % perl Makefile.PL
    % make && make test

Then install it:

    % make install

DOCUMENTATION

Plack::Middleware::ServerName documentation is available as in POD. So you can do:

    % perldoc Plack::Middleware::ServerName

to read the documentation online with your favorite pager.

Sorin Pop