Manhattan is small library providing intellisense-compatible access to various values in System.getProperties(). In certain targeted cases, functions exist to set those properties as well. Most of the properties are "read only" as far as this project is concerned because it doesn't make sense to mutate those properties.

In the Kotlin slack forums, Cedric Beust was bemoaning Kotlin's missed opportunity to expose certain properties as constants/functions.
Some property names require frequent lookups to get correct and are seemingly impossible to remember. Having members exposed to fetch values would allow for convenient autocomplete support removing some of those "burdens."

Using it is as simple as can be. Need the temporary directory? Simply call SystemProperty.tempDir(). What about the user's home directory? SystemProperty.userDir(). And so on. For some properties, Manhattan can even be used to set values as well:
SystemProperty.userDir("/some/other/path"). These functions can also be imported further reducing any verbosity.

Why the name? Because this project is about the most popular properties. And where do you find the most popular properties? Manhattan, of course!