KNOPPIX is the very useful OS based on Debian linux, and can be run from live CD. However, recent versions of KNOPPIX became bigger more than 4GB needs DVD. It can be installed on a USB flash media.
Easy2Boot is also very useful utility which can boot multiple OSs from ISO files stored in the single removal flash media. But, recent KNOPPIXs were very difficult (not impossible) to be treated by E2B because KNOPPIX ISOs (>4GB) were not stored in the FAT32 drive of E2B.
In KNOPPIX 9.1, CD image is also released after several years !! It can become loaded by E2B.
KNOPPIX9.1 with E2B is the very powerful and portable tool for our computing life!!