PPVOTE is described as 'It is just as important to receive as to give, especially when it comes to meetings and presentations'. There are four alternatives to PPVOTE for Linux and Online / Web-based. The best alternative is LiquidFeedback, which is both free and Open Source. Other great apps like PPVOTE are Pirate Feedback (Free, Open Source), ElectionBuddy (Freemium) and involv (Freemium).
Pirate Feedback is a fork of the software LiquidFeedback. In particular, the concept of chain delegation has been replaced by the concept of preference delegation. It also includes many bug fixes and improvements.
Electionbuddy is the complete online voting platform for running elections, polls, or referendums for boards, associations, schools, or anyone! It's free to setup and test electionbuddy, and it's free for less than 20 voters.