Control Version System fior linux?

[Salvador Santander Gutiérrez]

Hello, list.
We want to install a control version system for our developments, we've seen
cvs and Visual SourceSafe...
I prefer cvs but I've read cvs doesn´t allow file lock while another user is
changing it and we want this.
Visual SourceSafe allow this, but my question is:
Is there any control version system for linux that allow file locking?

Thanks.