How do you install an sh program?

[Benjamin Sher]

Dear friends:

This is an image manipulation program called XNView. I just downloaded 
the source tarball. But I can't figure out how to install this program. 
It must be simple. And I have installed sh programs before but there is 
usually an install.sh file. Not here. So, how do I install it, please? I 
wrote to the author but just got a reply that he is on vacation.

[sher at localhost XnView-1.68-x86-unknown-linux2.x-static]$ ls -l
total 180
drwxrwxr-x  2 sher sher  4096 Jul  1 04:24 app-defaults
drwxrwxr-x  2 sher sher  4096 Jul  1 04:24 bin
-rw-r--r--  1 sher sher 25778 Feb 18  2004 Formats.txt
-rwxr-xr-x  1 sher sher  2982 Feb 18  2004 install
drwxrwxr-x  2 sher sher  4096 Jul  1 04:24 lib
drwxrwxr-x  2 sher sher  4096 Jul  1 04:24 man
-rwxr-xr-x  1 sher sher   304 Feb 18  2004 nconvert.sh
-rw-r--r--  1 sher sher  4824 Feb 18  2004 ReadMe.txt
-rw-r--r--  1 sher sher  4644 Feb 18  2004 Usage.txt
-rw-r--r--  1 sher sher 59930 Feb 18  2004 WhatsNew.txt
-rwxr-xr-x  1 sher sher   302 Feb 18  2004 xnview.sh
[sher at localhost XnView-1.68-x86-unknown-linux2.x-static]$

[sher at localhost XnView-1.68-x86-unknown-linux2.x-static]$ ls -l
total 180
drwxrwxr-x  2 sher sher  4096 Jul  1 04:24 app-defaults
drwxrwxr-x  2 sher sher  4096 Jul  1 04:24 bin
-rw-r--r--  1 sher sher 25778 Feb 18  2004 Formats.txt
-rwxr-xr-x  1 sher sher  2982 Feb 18  2004 install
drwxrwxr-x  2 sher sher  4096 Jul  1 04:24 lib
drwxrwxr-x  2 sher sher  4096 Jul  1 04:24 man
-rwxr-xr-x  1 sher sher   304 Feb 18  2004 nconvert.sh
-rw-r--r--  1 sher sher  4824 Feb 18  2004 ReadMe.txt
-rw-r--r--  1 sher sher  4644 Feb 18  2004 Usage.txt
-rw-r--r--  1 sher sher 59930 Feb 18  2004 WhatsNew.txt
-rwxr-xr-x  1 sher sher   302 Feb 18  2004 xnview.sh
[sher at localhost XnView-1.68-x86-unknown-linux2.x-static]$

Thank you.

Benjamin