  This paper describes the architectural design as well as key implementation
details of the Open Source popt4jlib library
(https://githhub.org/ioannischristou/popt4jlib) that contains a fairly large
number of meta-heuristic and other exact optimization algorithms
parallel/distributed Java implementations. Although we report on speedup and
efficiency issues on some of the algorithms in the library, our main concern is
to detail the design decisions for the key parallel/distributed infrastructure
built into the library, so as to make it easier for developers to develop their
own parallel implementations of the algorithms of their choice, rather than
simply using it as an off-the-self application library.
