Trouble installing Quartus II Web Edition on linux (ubuntu 12.04)

Hi all, I am brand new to anything Altera related, and am not best with linux in the first place - so if the problems I'm having seem silly, please forgive me. And, I noticed there is a Linux forum section; should this be posted there?

I downloaded and extracted the tar.gz Quartus 12.1 Free from the altera download page.

From there, I tried to run the altera_installer_cmd (in 12.1_177_quartus_free_linux > altera_installer > bin ). When I do that, or try to run the altera_installer_gui, or the equivalent for the modelsim package, I get the following in the console. (sorry for the long paths)

/home/frogger4/Downloads/12.1_177_quartus_free_linux/altera_installer/bin/altera_installer_cmd: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory

So, I suppose the libz.so.1 library is important, but I really don't know what that is, or if this is even the right approach for installing.

I appreciate the help, and let me know if there is more info to provide!