If you are looking for commenting or forum services, you have these options:
Third-party integration – Most Magnolia sites today choose to integrate a third-party commenting or forum system. There are several on-premises and hosted services on the market such as Disqus, IntenseDebate and Discourse. Forum services have evolved to support features such as badges, reputation management and search engine optimization that are beyond what the Magnolia Forum module offers today.
Legacy modules – You can still get the Magnolia Forum and Commenting modules from Nexus for your own Magnolia bundles. The Forum module also requires the magnolia-core-compatibility .jar to be in the classpath to function properly.