Perl not Pearl
Source code can look very similar.
PHP has a lot more inbuilt functions.
You can do close to the same thing with each.
Perl is a great pattern matching language.
You can write horrible or spaghetti code with both.
Perl doesn't need a webserver to run
Source code can look very similar.
Perl doesn't need a webserver to run
The source code can look similar, but Perl is often a little more terse. Really tight Perl code looks a lot like line noise. If its obfuscated it's nearly impossible to puzzle out. PHP can be that way but you really have to work at it.
Technically, neither of them need a web server to run. You can run either at the command line if your system has the right modules installed.
I found a noticeable performance difference between the two - I think Perl is faster for simple scripts, but PHP probably performs better for more complex scripts that require library calls.
The analysis was done with a SOAP interface, and PHP consistently performed better. An equivalent script was written in both Perl and PHP.
I suspect this is due to the time required to interpret the Perl SOAP code.
It wasn't an exhaustive test, but if performance is a consideration, it's worth looking into.
Is there a functionality difference between Pearl & PHP?
Perl not Pearl
If its obfuscated it's nearly impossible to puzzle out. PHP can be that way but you really have to work at it. 
Linear Mode
