Looking for ways of interaction between the Customer and the Contractor through the web ...

After the last project, I thought about how freelancers interact with their customers during the execution of projects. And he began to look for something to fit his needs.

What we have:
The contractor periodically (once a day, once a week) sends the customer preliminary work. The customer is testing and posting comments. The contractor corrects them, sends them to the customer with marks that have been corrected, that a new one has been added.
Now all this happens through e-mail, communication in ICQ, and in the Word information about comments and corrections.

What I want and how I present:
I want all this to be in a single place, without any extra programs, i.e. via web interface
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Those. on a certain resource the client and the performer are registered. The contractor creates a project on it and gives access to it to the client (clients) and other performers.
Within the framework of this interaction takes place.
The customer creates notes, notes how critical they are, and when to execute.
The contractor sees and performs in order of priority. Marks what is done.

Having rummaged on the Internet, I found the only such resource ... www.teamer.ru

What you liked:
- Interface - simple, intuitive, convenient
- Calendar - deadlines are immediately visible and what needs to be done
- Free and Russian language - a separate plus for it

What is missing:
- there is no normal text editor to highlight in bold, color, etc.
- there is no possibility to attach files (although it is written in the description that is)
- need the ability to separately upload files somewhere (product updates)
- more flexible access settings. For example, users who can only watch information on the project, but can not write anything.

Actually the question: "Is there still something similar on the Internet?". IMHO would be useful to many freelancers.