I really like FreeScout. I’ve bought few modules and have been developing my own module for my needs. App is great, customizable, easy to use and more powerful than I thought. I use it every day, almost 4k tickets in the last month. It works well and made supporting our customers a better, faster, cleaner experience. Respect!

This is only great open source alternative for HelpScout. Using this for events and collaboration between teams for small projects. Indeed its very good option compared to paid services if you want to keep an archive of your data forever and prevent data access by service provider.