# Package Management in Photon OS with `tdnf` Photon OS manages packages with an open source, yum-compatible package manager called `tdnf`, for [Tiny Dandified Yum](https://github.com/vmware/tdnf). Tdnf keeps the operating system as small as possible while preserving yum's robust package-management capabilities. - [Introduction to `tdnf`](tdnf.md) - [Configuration Files and Repositories](configuration-files-and-repositories.md) - [Adding a New Repository](adding-a-new-repository.md) - [Configure a Repository](configure-a-repository.md) - [Adding the Dev Repository to Get New Packages from the GitHub Dev Branch](adding-the-dev-repository.md) - [Standard Syntax for `tdnf` Commands](standard_tdnf_syntax.md) - [Options for Commands](photon_admin/options-for-commands.md) - [Commands](photon_admin/commands.md)