There are no official repositories for Slackware. The only official packages Slackware provides are available on the installation media. However, there are many third-party repositories for Slackware; some are standalone repositories and others are for distributions that are Slackware-based but retain package compatibility with Slackware. Many of these can be searched at once using pkgs.org, which is a Linux package search engine. However, mixing and matching dependencies from multiple repositories can lead to two or more packages that require different versions of the same dependency, which is a form of dependency hell. Slackware itself won't provide any dependency resolution for these packages, however some projects will provide a list of dependencies that are not included with Slackware with the files for the package, commonly with a extension.
