The base installation includes various tools that generally help with application deployment. They are available on every Flying Circus NixOS VM. The package’s installation includes availability to run them manually and to compile your own software against them.
However, those are intended for short-term convenience. Linking against them may cause breakage of your applications in the long term.
Also, those packages are not providing running daemons (like OpenLDAP). If you need a managed component, those need to be activated explicitly.
All tools can be configured individually with dotfiles in the user’s home directory.