Originally Posted by va3dxs
Well no. My understanding is that .tar.gz and .tgz are the same thing? What I have done is if it is a specifically Slackware package I use installpkg. Otherwise I have gone through the whole routine. It's always worked with both .tgz and .tar.gz packages. And that incidentally is why I like Slackware so much - it always works if the dependencies are satisfied. That was very far from the case with the other 'easier' distros I tried.
Both are just compressed data. A Slackware package is never compressed as .tar.gz as far as I know, .tgz could be a package as well as a source tarball. You'll have to make sure when you download it whether it is a package or source files which need to be compiled. (that's what ./configure, make does)