[jberryman]

I've been with them for like a decade, and I don't think you've ever needed a specialized program. Use whatever you'd normally use to copy files over ssh, sftp, or ftp (but don't use ftp).

[iamben]

Yeah, this. They just use SFTP, which pretty much any program can do. Or just SSH.

But nothing web based - there's a little learning curve, but the forum support is fantastic.