This tool is very similar to ioncube tool. It uses the same protection method (converting source code into bytecode and protecting it with obfuscation).  Decoding procedures are similar to ioncube tool.

Both protections, sourceguardian (sg) and ioncube (ic), compile the source code for different PHP versions. sg saves all compiled versions inside the unique obfuscated file you get. sg also saves license file (if any) inside the unique file you get.