Java native runtime (jnr) is a collection of java libraries to make interfacing with os-level features easier. jnr uses an alternate method to jni or jna to achieve programming simplicity while still retaining performance.

the jnr-ffi package is a set of abstractions that build on the lower-level libraries implemented by the jffi package. jnr-ffi allows one to load native libraries without writing jni code by hand, or using tools such as swig.