This is a benchmark test of the performance of PHP with and without APC (Alternative PHP Cache). The test was performed on an Intel P4 1.7 Ghz with 1036028 kB of memory over a private LAN. The server runs PHP 5.3.3 on a standard Debian installation. Between each change of settings all related processes was restarted. https://unixsheikh.com/articles/benchmark-3-the-alternative-php-cache-apc.html
This tutorial explains how you can enforce a strong password for users on Debian. https://unixsheikh.com/tutorials/enforce-strong-passwords-in-debian.html
This is a minor tutorial in the usage of GnuPG to encrypt, decrypt, and sign emails and files. The examples provided in this tutorial has been tested on Debian GNU/Linux, Devuan GNU/Linux, Arch Linux and Ubuntu GNU/Linux. https://unixsheikh.com/tutorials/gnupg-tutorial.html
This tutorial describes how to set your hostname, domain name and fully qualified domain name properly. Both a mail server and a web server needs to run with the right hostname and domain name. https://unixsheikh.com/tutorials/how-to-set-your-hostname-and-domain-name-correctly.html
This tutorial was written when it was only possible to view videos on YouTube via Flash, however the tutorial is still useful if you need to download videos from YouTube, or some other video service, in an easily manner and watch them on your favorite video player. https://unixsheikh.com/tutorials/an-alternative-way-to-play-youtube-videos-without-using-flash.html