Machine Learning algorithm implementation

[María José Basgall]

Hi all,
I am a doctorate student in Computer Science and we are developing a
Self-Organizing Map (SOM) algorithm on MapReduce. I want to know about what
ML algorithm implementation is missing, because we want to make a
contribution to this project.
We checked out this page: https://mahout.apache.org/
users/basics/algorithms.html and we figured out that the most of algorithms
in the MapReduce column are deprecated, what is the reason for it? Do we
need to think in Spark instead of MapReduce implementations?

Thanks,
María José Basgall