Influitive - Influitive helps companies increase customer lifetime value and accelerate sales with the power of their own customer advocates. Inspire your customers to stay longer, share their experiences, and attract new business.
UserVoice - UserVoice integrates easy-to-use feedback, helpdesk, and knowledge base management tools in one platform that empowers users to speak and companies to understand.
Higher Logic - Private, secure online communities that stimulate conversation and ignite engagement.
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
Discourse - Discourse is an open source discussion platform built for the next decade of the Internet.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.