Added myself to /etc/sudoers but sudo still asks for password
None of your modifications of the sudoers file is needed if you start xampp with a launch daemon:


Create a file org.xampp.startup.plist  in /Library/LaunchDaemons with sudo touch/nano ... and the following content:

&lt;?xml version="1.0" encoding="UTF-8"?&gt;
&lt;!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"&gt;
&lt;plist version="1.0"&gt;
&lt;dict&gt;
        &lt;key&gt;Label&lt;/key&gt;
        &lt;string&gt;org.xampp.startup&lt;/string&gt;
        &lt;key&gt;ProgramArguments&lt;/key&gt;
        &lt;array&gt;
                &lt;string&gt;/bin/bash&lt;/string&gt;
                &lt;string&gt;/Applications/XAMPP/xamppfiles/xampp&lt;/string&gt;
                &lt;string&gt;start&lt;/string&gt;
        &lt;/array&gt;
        &lt;key&gt;RunAtLoad&lt;/key&gt;
        &lt;true/&gt;
        &lt;key&gt;StandardErrorPath&lt;/key&gt;
        &lt;string&gt;/tmp/org.xampp.startup.stderr&lt;/string&gt;
        &lt;key&gt;StandardOutPath&lt;/key&gt;
        &lt;string&gt;/tmp/org.xampp.startup.stdout&lt;/string&gt;
&lt;/dict&gt;
&lt;/plist&gt;


If you installed XAMPP somewhere else please modify &lt;string&gt;/Applications/XAMPP/xamppfiles/xampp&lt;/string&gt; accordingly.
chown/chmod the file:

sudo chown root:wheel /Library/LaunchDaemons/org.xampp.startup.plist
sudo chmod 644 /Library/LaunchDaemons/org.xampp.startup.plist

Load the daemon with:

sudo launchctl load /Library/LaunchDaemons/org.xampp.startup.plist

If everything runs well, you may remove the following part of the plist:

        &lt;key&gt;StandardErrorPath&lt;/key&gt;
        &lt;string&gt;/tmp/org.xampp.startup.stderr&lt;/string&gt;
        &lt;key&gt;StandardOutPath&lt;/key&gt;
        &lt;string&gt;/tmp/org.xampp.startup.stdout&lt;/string&gt;

Restore the default sudoers file with visudo:

...
root ALL=(ALL) ALL
%admin  ALL=(ALL) ALL

## Uncomment to allow members of group wheel to execute any command
#%wheel ALL=(ALL) ALL

## Same thing without a password
#%wheel ALL=(ALL) NOPASSWD: ALL
...