I know slightly close questions have been asked before but this question is a bit different.
 
We are a start-up company with a very limited budget and we are looking for a completely free Agile software development process tool without any limitation on the number of users. We don&#39;t want to have a limitation for the number of users because there could be a lot of people who would do small tasks for us and if they pass the number of user limit all of a sudden we&#39;ll have to pay a lot of money for the tool monthly.

It would be very useful if it could support:

 - Kanban board
 - Task hierarchy (so that you can define cards within cards)
 - Hosting the tool online (not download)
 - Commenting system
 - Different roles
 - Swimlanes

I have checked a lot of those tools here:

http://agilescout.com/best-agile-scrum-tools/

but I didn&#39;t find any that is absolutely free for unlimited users. Some of them also don&#39;t have a Kanban board. I checked Agilefant but its online version is going to be paid from 2014. I also checked Stackoverflow for this but none of the questions were targeting &quot;completely free tools&quot;.

Your help will be greatly appreciated.

All Kanban Solutions on Gang of Coders

Total of 1 Kanban Solutions

A completely free agile software process tool