"Libraries? Those are for users, not for sysadmins" – you may say. Correct. But, trust me, even if you don’t need to install them (with nonstandard options, e.g., because "they are needed for this latest version of our groundbreaking app!"), you will see the error messages from the user jobs, and the ability to distinguish system issues and userland issues is essential. The bad news is that there are tons of such libraries and frameworks. The good news is that most real apps use the most popular ones.