Tk development library for matplotlib backend
I am following the instructions at http://wiki.sagemath.org/sage_matlab to install the backend TkAgg for Sage's matplotlib. However, there is a missing step since the instructions assume that the Tk development libraries are already installed.
I am installing on a Red Hat Enterprise box behind a corporate firewall, so I am looking for a file to download with a name something like tk8.5-dev.tar. From there I can configure and make. I cannot find any such download on the web using Google or Bing. I can find downloads in the form of a .deb Debian package at pkgs.org/download/tk8.5-dev (which I believe is a binary file and so not usable on my system), but no source code tarball or rpm.
The answer to this question at wiki.sagemath.org/faq is specific to another flavor of Linux (use apt-get), which does me no good. Other questions on this site such as ask.sagemath.org/question/816/how-to-use-tk-on-sage just point back to the FAQ or the install page I referenced above.
Not trying to be nasty, but can I emphasize that solutions in the FAQ and the instructions should be as general as possible, and not only for one kind of system. All Linux varieties can work with tarballs. And please, I don't want to start a flame war on what's the best distro. Thanks.