When comparing Canny vs PHPBack, the Slant community recommends PHPBack for most people. In the question“What are the best user support & feedback services?” PHPBack is ranked 10th while Canny is ranked 14th. The most important reason people chose PHPBack is:
It has been already translated to Spanish and they are adding support for more languages.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Users don't have to sign in to give feedback
Pro You can choose whether search engines index feedback
You can choose between private, unlisted, or search-indexed. This will help drive users who Google for problems to find your official feedback forums.
Pro Integrations
Integrates with Slack, Jira, Zapier, etc.
Pro Multi-language support
It has been already translated to Spanish and they are adding support for more languages.
Pro Easy setup
PHPBack is very easy to setup, all you need is a server with PHP5 and MySQL installed.
Pro Open Source
PHPBack is open source, uses GPLv3 license.
Cons
Con No freemium pricing plan
Con Small community
PHPBack is fairly young (first stable version was releases in July 2015). Currently the community is small, which may make it more difficult to find help/support.
However, the developer is active on the github page and generally responds quickly.