MPIBlib is implemented in C/C++ on top of MPI. The package consists of libraries, tools and tests. The libraries implement point-to-point and collective benchmarks and different algorithms of point-to-point and collective communication operations. The tools verify algorithms and perform benchmarks. Their output includes the results of measurements and communication trees (for tree-based algorithms of collective operations). The results of measurements can be visualized by the gnuplot utility; MPIBlib provides the basic gnuplot scripts. The communication trees built in the tree-based collective algorithms can be visualized by the dot utility (a part of Graphviz).