The best replacement for confluence is sharepoint.

The best alternatives to confluence are rated as following:
★★★★★  sharepoint
★★★  convergence
★★★  mediawiki
★★★  jira
★★  wiki
★★  google sites
★★  twiki
★★  sharepoint 2013
★  asana
★  jive
★  alfresco
★  onenote
★  redmine
★  pbworks
★  basecamp
★  wikimedia
  yammer
  sharepoint 2010
  podio
  confluency

Your alternative for confluence is not listed? Suggest!
Speaking about confluence, one probably shouldn't forget about crowd.

Other search terms related to confluence and their ratings are:
★★★★★ crowd
★★★ jira
You have in mind a companion for confluence and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of confluence in all years. Click on graph for more.
confluence
sharepoint
convergence