OK, these guys have some questions:
Do you have a website or run even a web server and want to secure the traffic between your visitor's browser and the web site? Did you find out that, in order to make your site SSL aware, you'll need a SSL (Secure Sockets Layer) certificate? Were you also surprised to find out that such a certificate can cost you hundreds of dollars, and that they are only valid for one year? For what, you might ask yourself?
[ StartCom Free SSL Certificate Project ]
And basically the answer is that if they don't check out people, anyone can get an SSL certificate, and the little lock will mean nothing but traffic is encrypted. Part of what that is supposed to provide is 3rd party confirmation about who you are dealing with. Clearly installation of their root certificate will make your machine somewhat more gullible, and you won't know for sure that when you see the wee lock that you are dealing with the company that says they are that company.
However, they also point out that few people fully understand all of that stuff, and CAs don't check too much to issue a certificate. Most importantly for web developers this means the availability of a true, valid, painless, SSL certificate for localhost for all of your development needs. Now that's something to get excited about.
Update: StartCom has asked me to "check out our project again", as then have increased their offerings and my above statement is no longer true.