Rather earlier than 1997, though full dependency resolution and such came around then (I actually thought it was earlier). APT in particular saw its first release in 1998. It was built as a front-end to the earlier dpkg (anyone else remember dselect?), released in 1994.

Ian Murdoch's observation on package management advances driven by Linux, and Debian in particular, are on mark (from the Wikipedia article).

Like apt/yum, but with multiple sandboxed versions and installable in users' home directories.