Analysing the Maven Central Repository during the second half of 2018, a group of scientific researchers led by Benoit Baudry, Professor in Software Technology at the KTH Royal Institute of Technology, reveals that Maven Central contains more than 2.5 million artifacts, a real treasure of extraordinary software development. More than 17% of the libraries have several versions that are actively used by a large number of clients.
However, 1.3 million dependencies declared are actually not used. Also, a vast majority of APIs can be reduced to a small, compact core and still serve most of their clients.
For a more accurate exploration of the Maven Central ecosystem, read Benoit Baudry's article posted on Medium.com:
A journey at the heart of 2.4 million Maven artifacts.