Enigma Virtual Box – Best free single-executable portable app maker

As a completely free and lightweight (less than 5 MB) software virtualization/packaging tool for Windows, Enigma Virtual Box is capable of packing all the relevant files/folders of some software into its main program (main input file, supports both 32-bit & 64-bit EXE files), thus makes it to be a single-executable/portable app for most Windows versions (2000 or later).