BG-Tiny Linux Bootdisk is a Linux bootdisk that does not use a ramdisk, so it will run on computers with very little RAM. It is basically a somewhat extended fork of Tiny Linux Bootdisk. It is based on Linux 2.4 series, uClibc, and BusyBox. It includes dosfsprogs, e2fsprogs, gpart, lilo, and ms-sys. Supported filesystems are ext2, ext3, iso9660, tmpfs, and vfat.
G4L is a hard disk and partition imaging and cloning tool. The created images are optionally compressed, and they can be stored on a local hard drive or transferred to an anonymous FTP server. A drive can be cloned using the "Click'n'Clone" function. G4L supports file splitting if the local filesystem does not support writing files larger than 2GB. The included kernel supports ATA, serial-ATA, and SCSI drives. Common network cards are supported. It is packaged as a bootable CD image with an ncurses GUI for easy use.
MBCD (MultiBootCD) is a shell script to make a customized CD-ROM that can boot any kind and any number of image files. Currently, 4 types of images are supported: floppy images (1.2M, 1.44M, or 2.88M), Knoppix-like images, kernel-binary images (e.g. memtest86), and the Windows XP Recovery Console.
PXE Knife is a tool for booting various floppy based utilities via syslinux, allowing them to be booted off a CD, a hard drive, or over the network via PXE. PXE Knife can be used with a number of commonly used tools such as hard drive manufacturer's utilities, memory testers, Linux recovery disks, Windows password changers, pre-configured PXE Knoppix booters (just add DVD), and a number of other utilities. It takes advantage of syslinux's menu system, so it's easy to navigate.
Salvare (from the Latin "to rescue") is a small Linux distribution designed for small, credit-card sized CDs which typically hold around 34MB. More Linux than tomsrtbt but less than Knoppix, it aims to provide a useful workstation as well as a rescue disk. In addition to providing a rescue environment similart to tomsrtbt, it adds OpenSSH, a graphical and text mode Web browser (Links), security tools such as chkrootkit, nmap, and tcpdump, the ability to apt-get install additional software from Debian into tmpfs, the ability to run entirely from RAM, and much more. It's also customizable using a simple source-code based package management system.
alcolix is a minimal Linux rescue distribution with the goals of being small, compatible, and very usable. It has a cozy shell and a multitude of partition rescue/editing tools, all based on up-to-date releases (e.g., 2.4.x kernel with USB support). It uses cpio.bz2 data disks and has a full GRUB bootloader, memtest86, and more.