Since you mentioned an IIS server, it would be very simple to throw together small ASP pages to call your "cool" routines.

Dim Obj as Object
Set Obj = CreateObject("ProgID_of_your_Perl_DLL.app")
Obj.CoolRoutine
[download]

Update:
It was late when I first posted this so forgive me for not providing a pure Perl solution. This is PERLmonks after all and it ate at me so bad that I climbed back out of bed to add this to my post:

Once the .dll is on the server and registered properly you can call it via you Perl CGI scripts by adding:

use Win32::OLE;

my $obj = Win32::OLE->CreateObject('ProgID_of_your_Perl_DLL.app');

$obj->CoolRoutine();
[download]

Active State's PerlApp will genrerate a Windows executable from a perl script by bundling it with the perl executable. It does hide your code and if you decompile the app the raw perl code is not immediately visible. Some of us did post a node or two about how to crack scripts out of this (pretty easy) so don't think it is particularly secure because it is not. It will stop the casual but not the determined. I would advise a solid contract along with the usual back doors and other *security features* you might add to ensure you can screw your client if they try to screw you ;-)

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

Hire a good system administrator to configure your web server properly so that users won't see your "cool" code. :)

I'm afraid you're SOL. Perl is an interpreted language. Although there are options available for obfuscating code, you have to provide your sources to perl to get them to run. If you insist on providing binaries only, you'll have to find another way to code your web site.

---
print map { my ($m)=1<<hex($_)&11?' ':'';
$m.=substr('AHJPacehklnorstu',hex($_),1) }
split //,'2fde0abe76c36c914586c';
[download]

Strange, ... None of the dynamic webpages I wrote can be seen by the user. All my programs either result in pure HTML or provide XML which is then server-side transformed into HTML, again providing only HTML to the client.

Can you point me to a web-site you guys wrote which sends Perl-code to the browser? I assume you are not talking about Perlscript being run on the browser?

Update: Sorry, I read past the part that says the code is deployed on the client's web-site. In that case, the solution is to have a good contract with the client to protect your copyright. Oops, my training as a lawyer is showing.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law

The bottom line is as given by tachyon and CountZero, though you should read
perldoc perlfaq3 How can I hide the source for my Perl program? for the reasons why.