Ubuntu Server: What version of Apache am I running?

The quickest way to determine what build or version of the Apache webserver you are running on your Ubuntu Server is simply to call up a terminal and run the -v switch on the apache2 command.

This will output both the version as well as a date of when this server version was first built.

In practice:

sudo apache2 -v

Pleasingly enough, this will also work if you want to find out what version of PHP you are running on your Ubuntu Server, as well as what version of MySQL (both client and server) you are running.

Again:

#PHP version your Ubuntu Server is running:
sudo php -v

#MySQL Server version your Ubuntu Server is running:
sudo mysqld -V

#MySQL Client version your Ubuntu Server is running:
sudo mysql -V

Nifty.