In which directory should I install programs on Linux?

Question

I use Linux for 2 years at my work and I still confused where should my installed programs remain. Now I use /opt/<program> e.g. I've installed vim73 from sources there (reason not to use package manager is there is no 7.3 version of VIM in my sources e.g. /etc/apt/sources.list on my Ubuntu).

But all my programs I installed from sources previously are scattered among FS everywhere like PHP 5.3.6 remains in /opt/local/php53, apache in /etc/, vlc in /etc/mutimedia etc.

Is there some convention I can follow?

Answer 1

Absolutely. It's called the Filesystem Hierarchy Standard.