Ask Slashdot: Heterogeneous Network Backups w/Linux?

drix asks: "Like many I'm running a Linux gateway between my home network and cable internet connection. Naturally, I'd like it if my Linux server, 4 Win 98 boxes, and iMac could do a nightly backup. The problem is I only have one tape drive, which is, of course, situated in the server. So my question is what software exists that, a) runs on Linux, b) exists in a client server form, where the server runs a "backup daemon" that each client connects to to backup its respective hard disk each night, and c) has clients available for Windows and optionally Mac? I guess the analogous NT ware would be Seagate Backup Exec, which runs on an NT server and polls NT workstations nightly for any changed files, and then uses delta file compression to zip those changes to the server's tape drive. I don't need anything that complicated, but I must have the basic ability to move the files."