These are modules that can be loaded into the Linux kernel, providing extra support for mice, CD-ROM drives, ethernet cards, and other devices. See these files in the "docs" directory for more information on loading these kernel modules: CDROM-HOWTO, ELF-HOWTO, Ethernet-HOWTO, Ftape-HOWTO, HAM-HOWTO, Hardware-HOWTO, Kernel-HOWTO, NET-2-HOWTO, PCI-HOWTO, PCMCIA-HOWTO, SCSI-HOWTO, SCSI-Programming-HOWTO, Serial-HOWTO, Sound-HOWTO, UMSDOS-HOWTO. Also see the documentation in /usr/doc/modules, and the Documentation directory in newer Linux kernel source. (/usr/src/linux/Documentation) As a simple example, this line in your /etc/rc.d/rc.modules will load the driver for a 3com 3c509b ethernet card (PnP mode on the card disabled): /sbin/modprobe 3c509 Note that this must happen *before* using ifconfig on eth0 or setting up eth0 related routes! Here's how this will look when you boot your machine: INIT: Entering runlevel: 3 Going multiuser... loading device 'eth0'... eth0: 3c509 at 0x360 tag 1, 10baseT port, address 00 a0 24 28 ec a0, IRQ 10. 3c509.c:1.12 6/4/97 becker@cesdis.gsfc.nasa.gov eth0: Setting Rx mode to 1 addresses. Mounting remote file systems... Starting daemons: syslogd klogd portmap inetd lpd mountd nfsd If you've installed the modules.tgz package, you'll have all of these modules installed on your machine under /lib/modules/ already. So, to start using kernel modules you'll want to edit the /etc/rc.d/rc.modules file to select which modules you want loaded at boot time. You can also use kerneld, a daemon which load and unloads kernel modules automatically on demand.