What are some alternatives?
When comparing Elgg and Oxwall, you can also consider the following products
BuddyPress - WordPress social networking in a box.
HumHub - HumHub is a free social network software and framework built to give you the tools to make teamwork easy and successful.
Minds - The open-source, encrypted social network that expands your reach for using it.
Ultimate Member - The easiest way to create powerful online communities and beautiful user profiles with WordPress.
Facebook - Connect with friends, family and other people you know. Share photos and videos, send messages and get updates.
SocialEngine - eXo Platform