You will notice differences certainly. Most noticable will be differences in the standard userland utilities. FreeBSD does not use GNU ls, GNU cp, and so on. For example, if you're attached to a colorized ls, you may want to alias ls to "ls -G". It does use GNU grep, though. The default shell is a much simpler and less bloated shell than GNU Bash, which is the default on most Linux distributions. If you are attached to bash, that may be one of the first packages you will want to install. The ports system has been the standard way to install software on the various BSDs. Ports downloads the source code, builds it, and then installs it. It's nearly entirely automatic. To install bash, for example, do this as root:
cd /usr/ports/shells/bash && make install && make clean
If you don't do a make clean at the end, you will leave the built source code lying in the ports tree. Many ports have pre-built packages that can be downloaded if you prefer not to waste time building it and don't need to customize it. To install bash as a package, this should do it:
pkg_add -r bash
You can find most any common program in ports including Gnome 3, sudo, rsync, or what ever else you need. A great website for navigating ports is FreshPorts. You also should get familiar with the FreeBSD Handbook.
Oftentimes /opt is used for such a purpose.
The use of /opt for add-on software is a well-established practice in the UNIX community. The System V Application Binary Interface [AT&T 1990], based on the System V Interface Definition (Third Edition), provides for an /opt structure very similar to the one defined here.
And games are additional (i.e. nonnecessary) software.
Best Answer
You can find the Filesystem Hierarchy Standard (FHS) version 2.3 at pathname.com/fhs. There is a section about the
usrhierarchy. The FHS lists/usr/localas a required directory and writes:Furthermore FHS writes:
The different Linux distributions usually don't write software to
/usr/local. Instead each file is placed into the filesystem according to the FHS.If you install software from source (
./configure && make && make install) without specific options this software copies itself usually to/usr/local.The default directory for MacPorts is
/opt/local. The MacPorts guide has a description of the internals.