I thought I was a power user but apparently I have a little more to learn.

I wanted subversion for my N900 to sync some document repositories. After some searching, I found it was as easy as "sudo gainroot, apt-get install subversion".

So why is subversion available from the command line but does not show up in the graphical package manager? What other useful tools are available command line install only?

David

I think package manager reads only user section. This depends where the developer puts it.
You can see this with: apt-cache show package_name

For example:
apt-cache show subversion
says:
Section: devel
won't show in package manager

while for example:
apt-cache show fbreader
says:
Section: user/utilities
will show in package manager