One of main goals while developing this library was easiness of use. Libraries with complex API are usually slow to be accepted by the community, and often libraries that can do less but have a cleaner API are preferred over more sophisticated libraries that have a user-unfriendly API.
The library is accessinble both from plain C and C++ programs. Since the library itself is written in C++ (without use of bloated and bloating libraries like libstdc++ or boost), the C interface is a (very) thin wrapper around the C++ classes. The overhead imposed by the wrappers is negligible.