UNetbootin Alternatives

With balenaEtcher people can create an installation media of your operating system by burning the image on a bootable flash drive. The software, that was previously known as Etcher, is developed by Balena and the open-source community and released free of charge under the Apache-2.0 License. balenaEtcher can be downloaded and used for following operating systems: macOS, Linux and Windows.

With Rufus you can format and create bootable USB drives. Rufus is free and open source and can format FAT, FAT32, NTFS, exFAT, UDF, ReFS that works across USB flash drives, keys, and memmory sticks.

A really simple open-source, GUI application that writes compressed disk images to USB drives and creates backups. USBImager is avalible for Linux, macOS, and Windows.
 

MultiBootUSB is a cross platform software that allows you to install multiple live linux on a USB disk non destructively and option to uninstall distros. MultiBootUSB is written in Python and is released as free and open-source software under the GPL-2.0 License.

Win32 Disk Imager is a tool for creating bootable USB drives.

Ventoy is a free and open source tool that you can use to create bootable USB drive for ISO,WIM, IMG,VHD, and EFI files. You can copy many files at a time with Ventoy, instead of formating disks over and over again. Ventoy supports x86 Legacy BIOS, IA32 UEFI, x86_64 UEFI and ARM64 UEFI.