It is easy to use, has many features including search capabilities via Apache Solr which makes it one of my favorite tools for knowledge management in our organization! The interface could be more intuitive but that's not really an issue with this product as I am able find what i'm looking at without too much difficulty or help from other users who know how things work better than me :) We are using twikki wiki internally within TCS (Theatre Consultants Services) so we have been very happy thus far especially considering there was nothing else out their similar enough when starting up! Currently trying Twilio SMS integration through Sinch API since its free trial period expires soon :).
Using internal communication tool between team members/employees across different projects / departments etc.