Most steps must be done as root.

Apache Configuration

Apache2 webserver >= 2.2.x
the following Apache modules should be enabled
- rewrite / filter / deflate / headers / expires
Configure Vhost:
- DocumentRoot must point to FOO/public
  where FOO is the installation root and is writeable for the installer
- include_path set include_path to .:FOO/library/zend:OTHER_PHP_PATHS

...

PHP Configuration

latest PHP 5.6 (PHP 7 not supported yet) 7.3 with the following extensions installed and enabled
- dom / fileinfo / gd with Freetype-Support / iconv / mbstring / pdo_mysql / zip / intl / json / curl (ensure that your local CA list is up-to-date)
Check error_logging configuration
- set error_log to an appropriate file
- set display_errors to Off
Check upload sizes:
- post_max_size=600M
  upload_max_filesize=600M
Check if php can send E-Mails

Check max_execution time for production environment and large file imports:

max_execution_time=3600 #for production instances and large files in imports to be on the save side

Check memory_limit for production environment and large file imports:

memory_limit=1024M #or higher, if possible for production instances and large files in imports to be on the save side

Fix file permissions of installation

use the installer here!
configure OpenTM2 (and/or other TM/MTs) URLs
configure TermTagger URLs
reenable emails (disabled in installation.ini by installer)
- resources.mail.defaultFrom.email must be an email which can be used as sender (from the server) and must be configured to receive mails. It receives the error mails.
Fix file permissions of installation
Change default users - create client specific users
- remove listing of default users
Change client-specific logo stuff etc