What are some alternatives?
UseResponse - Open-source, self-hosted customer feedback software, live chat and helpdesk system that you can install on your server. Organize documentation using knowledge base and get feedback from social networks with centralized system
XMind - XMind is a brainstorming and mind mapping application.
Sideways 6 - Sideways 6 is the best way to involve your employees in innovation.
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Spigit - Spigit is a software program designed to help CEOs and industry leaders to tap into the creativeness of their employees. It brands itself as an idea management tool. Read more about Spigit.
MindManager - With MindManager, flexible mind maps promote freeform thinking and quick organization of ideas, so creativity and productivity can live in harmony.