Finally decided to start using a version control system. The choice fell on git (on bitbucket).
There is a project (a web portal) is stored on the hosting (absolutely working version). There are 3 people who can modify the code, adding new modules and features. All these changes are on test subdomains (each has his own, which is updated periodically), at the end of the development the modified code is transferred to a working website.
As theoretically, to organize the work for the change of the working draft were preserved in history, and how to upgrade to test versions of each of the developers?