why some software appear on the "add/remove" dialog, while some other only show on synaptic ?

As best as I can tell, the add/remove tool gives new Linux users a simple interface to add some of the most common/popular packages. I don't know that everything there is popular and I'm sure some popular packages are left off. Synaptic should give you access to everything available - including all the libs that make no sense to most people. Add/remove just gives new users a potentially more familiar environment for adding commonly asked for packages. Don't forget to change the "show" menu to "all available" to get the widest selection.

Jim,

I'm actually asking that because a very popular package, checkgmail, is left off that list. It's not a weird library - it's the best program for getting gmail notifications on gnome, imho. And it's left out, one can only install it via apt-get on synaptic.

They include the KDE version, kcheckgmail, but not the original checkgmail one.

So I just wanted to know who decide what goes in, and why, so I can suggest that they add checkgmail to the list.

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

reopening

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

reopening

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

re-opening.

That's because Add/Remove shows only software in main and restricted repositories.

Andrea,

Even when I select to show "All available applications", it doesn't get listed on.

Add/remove only shows a subset of all available apps. To see them all (at least all for the repositories you have enabled) use Synaptic (system-admin). To add more repositories check https://help.ubuntu.com/community/Repositories. Be sure you only add "safe" ones.

Jim,

Thanks for your answer. Yes, I know that only a subset is shown, and that there are other ways to add the ones that don't show.

What I'm asking is :

1. Who decides what shows and what doessn't shows
2. What are the criteria to decide what shows and what doesn't

Thanks Jim Hutchinson, that solved my question.