Just so you will know, emerge is the package management tool for Gentoo linux. It is “the command-line interface to the portage system” (from emerge man-pages).

On with my top-5:

#1 emerge –sync
This command synchronizes your local collection of packages with the latest sources available from Gentoo. You should sync your portage directory at least weekly. You can’t get more important than having the latest, up-to-date packages to chose from. This is what keeps your system on the “bleeding-edge” of the linux world.

#2 emerge -av
The -av switch to the emerge command tells emerge to ask (-a) before it performs any actions and, to be verbose (-v) with the details of what it is going to do. This is usually very important because you will (IMHO) want to check the USE flags on a particular package before installation. (USE flags are not addressed in this post and, will be addressed at a later date. Check the Docs if you want to know right now)

#3 emerge -u ( –update)
The -u switch tells emerge to update the packages installed on your system. You would want to use the –sync command just prior to the -u switch so that you are sure to upgrade to the latest package available. ( Again with the bleeding-edge thing)

#4 emerge –resume
The resume switch gives the user the ability to restart the last emerge session. Lets say there was a power outage or, for some reason emerge needed to be stopped in the middle of upgrading a large number of packages. The –resume switch will allow you to restart the session immediately after the last installed package.

#5 emerge -c ( –unmerge)
This one is almost self explanatory. Unmerge means remove, Uninstall. Use the to completely remove a package from your system. Do not use this command unless you really want the package removed from your system. Although there are times when you want a package removed. If this is the case then, the -c switch is the one for you.

I can’t compare emerge to Debian based package management utilities. I haven’t used those enough to do so. I can compare them to distros like Fedora and Suse. My opinion is that emerge is a more efficient and controllable system of package management.