I have found that using a Bullet Journal ( a nice pen and paper solution) I can cover my Calendar, Tasks, and even general notes rather well. You can find instruction here: http://bulletjournal.com/ , but the best part is that it will work with any notebook you have lying around!

For Kanban's, I have used Trello, but got a little annoyed. I recently found this personal Kanban project: https://github.com/greggigon/my-personal-kanban It's use is very simple, and I find that it works well for me. A little difficult to share among a group though.

Finally for All the rest of my documentation: Keepnote http://keepnote.org/ This glorious little tool handled nearly anything you can throw at it. It supports Windows and Linux ( I am not certain about Mac), and it is search-able. I have used it from all my work related notes, specifically for debugging solutions, like Binding Exceptions in Telerik.