I do web development, I am interested to know if I can use the freebie version of s-drive to test my new sites with a given domain name that has not been transferred to any hosting site.

I only see s-drive for Visual Site Designer. So can I use it for htlm and upload with filezilla or is there an option on the coffee cup html editor?

You can use Direct FTP which has a default system setup for your S-Drive account.

The HTML editor can publish to S-Drive also. It's not a one file selection process though. It's a sync all files, so all the files get published.