PhpSysInfo

phpSysInfo is a PHP script that displays information about the host being accessed. It will displays things like Uptime, CPU, Memory, SCSI, IDE, PCI, Ethernet, Floppy, and Video Information.

phpSysinfo would have to be one of the most easiest applications to install.

CentOS

yum -y install httpd php php-xml php-mbstring

cd /var/www/html
wget https://github.com/rk4an/phpsysinfo/tarball/master -O phpsysinfo.tar.gz
tar xvzf phpsysinfo.tar.gz
rm -f phpsysinfo.tar.gz
mv  phpsysinfo-phpsysinfo-d06b02a sysinfo
mv sysinfo/phpsysinfo.ini.new sysinfo/phpsysinfo.ini
cd

Debian

apt-get -y install apache2 php5

cd /var/www
wget https://github.com/rk4an/phpsysinfo/tarball/master -O phpsysinfo.tar.gz
tar xvzf phpsysinfo.tar.gz
rm -f phpsysinfo.tar.gz
mv  phpsysinfo-phpsysinfo-d06b02a sysinfo
mv sysinfo/phpsysinfo.ini.new sysinfo/phpsysinfo.ini
cd

Access

Now all you need to do is from a WEB browser type in your servers IP address or FQDN followed by /sysinfo and see all the wonderful information. You will need to make sure that the WEB services are installed and running for this to work.
Example

http://192.168.1.11/sysinfo