Has anyone made a family tree site, and/or have any suggestions for some cheap, simple software for creating one?

I’m considering making a site for the Brown side of my family. Every year we have a Christmas Reunion, and it’s getting harder and harder to keep track of everyone (people marrying/changing names/having kids/etc.). We do a gift exchange, and it’s hard to keep up with any changes. For example if you’re told you got “Jennifer Michaels” as the person to buy a gift for, you may not remember that it’s the person you know as Jenny Brown who recently got married, or that Alex Brown is a 4 year old girl, and not the 13 year old boy you were thinking it was.

Ideally, the software could have more than one user, so I could enlist the more tech-savvy of my relatives to update their own info. PHP and SQL is preferable.

I’d like to make the go-to site for the Who’s Who in the Brown family, but I don’t need a lot of bells and whistles. I know there are several commercial sites out there that will host a family site like this, complete with a family tree showing how everyone is related, but since I’ll likely be alone in this, I don’t want to pay $50/year out of my own pocket for a site that’ll likely only be accessed in December when people scramble to try and pick an appropriate gift for the exchange. Plus, I don’t really want another site to have to follow all the time (like Facebook, blurgh) so I don’t want to have a gallery, or individual status updates, or any of that other social media stuff.