trello
We use Trello in our office for keeping track of projects etc and it proves very useful.
However, we only use it internally. After engaging in about 100 emails with a client over a week it has prompted me to possibly setup a 2nd client external board. Where both myself and clients can add/edit lists and cards.
Is there a way you can do this, but only restrict access for the client to a specific list including its cards. But obviously we would want clients to access or use other lists.
As stated by Rich Armstrong, Director of Customer Operations
there are no plans to offer a self-hosted version in the future.
As described in their privacy section
Access to your data is tightly controlled internally. Unless we hear different from you, we will only be able to access and view the information you make public. We do run anonymous usage profiling over our database, but no one can inspect your data without your say-so.
This line does not say how well they will handle confidential data but that is a risk you are going to have evaluate based on the critical nature of your data.
As I always wanted this feature, I wrote a bot that keeps cards in sync across Boards.
See if it suits your needs. From the description:
Hello, my name is cardsync and I am a bot designed to keep cards in sync, which means I update the content of one Trello card to reflect changes made on other card.
Also, here's a small gif animation that shows it in action:
Best Answer
There are no per-list permissions in Trello at the moment. The best solution would be to create a board for each client. This has the advantage that if the communication with the client gets more complicated, you can structure the conversation by having multiple lists in the board.