What are your top binary library dependencies?

On the #toolchain IRC channel, jawnsy and I were discussing how cool it would be if there were Alien::* packages for the top 10 or so binary libraries that people use with Perl. I.e. things like libssl, libxml2, libexpat, etc.

I don’t know what it would take to make that happen, because getting Alien packages right across platforms is tricky, but a first step is figuring out what libraries people wind up needing the most.

If you install libraries/headers by hand, what do you wind up using most often? Please answer in the comments.