Versioning

I would like to have a stable/current version, the beta version, the alhpa version and the oldest versions.

Also, my project has clients and each client can be in different version.
For example X clients are in 1.1 version and Z clients are in 1.2 version and some others are in 1.3
When a client log in to my system, i know his version and i would redirect him to the correct version of my project.

If you can suggest me something else, i would like to hear it!

Thank you for your response.