Some Software Manager for Mac OS X like Synaptic in Ubuntu
There are two main systems for unix software on OS X: MacPorts and Fink

Fink is akin to (and iirc based on) the Debian/Ubunutu apt system: it delivers pre-compiled binaries. MacPorts is related to the older BSD Ports collections: rather than pre-built binaries, it containers pointers to the original source + patches required to make that source work on your platform (and with the other apps that you've installed via ports).

There's also a newer tool called Homebrew which I've not used; but it claims to provide better interoperability with things you've installed by hand, and rely more on the native Mac libraries instead of just the installed libraries.

A quick search shows a variety of questions already talking about Macports and Fink and differences between them.

Source: https://superuser.com/a/92885/256923