Apt (advanced-packaging-tool) is an excellent tool to install/remove programs and packages on linux. The problem is that programs and packages sometimes are too old.
To help solve this problems you can use an external repository using ppa (personal package archive) to get more recent versions of your software/packages.
Let's take nginx for example. The version on apt is 1.1.19 (at the time I wrote this), but you can find the newest version using the nginx/stable ppa repository which is 1.2.6.
Let's see how it works:
add-apt-repository ppa: < user > / < package >
Update your apt packages
apt-get install nginx
Find more repositories for your linux distro on: https://launchpad.net/