Ultimate Boot CD vs UNetbootin

Ultimate Boot CD (UBCD) gathers floppy-based diagnostic utilities into one bootable ISO. After starting from the CD, users choose a program from a text menu; that program runs from a virtual floppy created in memory. The collection includes stress, memory, disk-health, and GPU testing tools. The listed release is V5.3.9, described as a maintenance release while the project says it is largely in hibernation. UBCD does not support UEFI boot, and its download guidance recommends enabling CSM Boot on UEFI machines. USB-memory boot is described as experimental on supported hardware. The download page publishes MD5, SHA1, and SHA-256 checksums for the ISO and distributes it through P2P plus volunteer HTTP mirrors. Utilities include freeware, shareware, and open-license programs with differing terms; some freeware bars commercial redistribution. Instructions explain how to customize a disc. UBCD Live is a separate early-beta Debian-based rescue CD. The listed plan is a free 803 MB ISO download.

UNetbootin creates bootable Live USB drives for Ubuntu and other Linux distributions, allowing installation without burning a CD. It can download a supported distribution or use a Linux ISO already on the computer, and the listed targets are a USB drive or hard disk. Built-in downloads include Ubuntu, Debian, Fedora, Arch Linux, Linux Mint, and FreeBSD, as well as system utilities such as Parted Magic and SystemRescueCD. The site says most Linux ISO files should work, though some require extra boot options or changes, and some cannot boot from USB as-is. Non-Linux operating system ISOs should not be expected to work because they use a different boot mechanism. UNetbootin is available for Linux, macOS, and Windows, and is free; donations are accepted. The source code is available on GitHub under GNU GPL Version 2 or above. Linux download options include an Ubuntu PPA, 32-bit and 64-bit binaries, packages for several distributions, and source code.