ILIAS needs an apache webserver and php5 with some modules. To improve php performance, eaccellerator can be installed. Some php5- modules like ldap or radius serve for external authentication for ILIAS. If you solely use the ilias database for user accounts, some modules can be omitted.

phpmyadmin is installed to give an easier access to the database in case of errors. It requires an own password for access and needs to know the database root user's password. Since phpmyadmin may be a security risk, diecide if you want to install it.

apt-get install apache2
apt-get install php5 php5-gd php5-mysql php5-xsl php-pear php5-ldap php5-radius php5-mcrypt php5-xmlrpc php5-dev php5-curl curl

and optionally (see above)

apt-get install phpmyadmin

Since ILIAS uses a lot of php-code, a speedup in the execution of php dramatically increases the performance of the system. Approaches for this are:

• Installation of eaccelerator
• Installation of the module php5-xcache (easier to install and maintain as eaccelerator, but with some problems with apache 2.4 in jessie)
• Installation of php-apc (which works in my jessie/ILIAS 5 environment)
• change to nginx webserver for cgi and/or use of hhvm

Some adminsitrators want to restrict php applications only to use files located in a separate directory and don't execute binaries from /bin or /usr/bin. In this case, create a separate directory like /srv/cgi-bin and copy all the external utilities required by the setup (zip, unzip, convert, ffmpeg, htmldoc, java) into this directory. Remember that these utilities will not be updated during system upgrades; you have to copy updates manually.

Newer versions of apache restrict access from the web to the html documents to certain directories. Probably you have to modity the apache2.conf file to a new document root if you don't use the standard /var/www for your ILIAS installation.