peekabot is a versatile 3D visualization tool targeted at robotics researchers and developers. It's multi-platform, general purpose, easily extendable, scalable, and does not depend on any other frameworks to function. It also provides some functionality for interacting with your robots using the GUI. You can test your algorithms in both simulated and real environments. The only requirement is that the device can use TCP/IP.
Sunrise Sunset is a Python package that can determine the sunrise and sunset based on a given altitude zenith. It has two public methods. The first returns the sunrise and sunset in a tuple. The second returns True or False depending on whether the supplied date/time is during the night or day. The constructor takes three arguments, a date, latitude, and longitude. There is one keyword argument for changing the default zenith, which is set to "official". The zeniths are "official", "civil", "nautical", "amateur" (astronomical), and "astronomical". It does not rely on third party packages, but you may need something like pytz to create dates with timezone info.
libcfp analyzes and parses the syntax of a user-supplied chemical formula in ASCII notation. It does not know anything about the semantics of real world physical element characteristics. But it requires no external library dependencies and uses namespace std:: only. Furthermore, it uses UnitTest++ during development to ensure consistent behavior of formula parsing.