Coding collaboration

[Connect]

I am doing a programming project with a freelance programmer. We use mainly ColdFusion. It is a collaboration between myself and the freelance programmer, in two different working location (not same office)

Now, we find it very difficult to avoid us overwriting each others file. Is there any solution that can help in this scenario? Can CVS be used?

[LAMP]

Use CVS
nongnu(dot)org/cvs/
There is a nice Software as well (which I cannot remember where to find)