Merlin is a MOS Technology 6502 macro assembler developed by mathematics professor Glen Bredon for the Apple II under DOS 3.3.
This means that while it is essentially new from the ground up, it adheres to and follows almost all of the conventions associated with TED ][+, in terms of command mnemonics, pseudo-op's, etc.
The original TED ASM was written by Randy Wiggington and Gary Shannon."
A related utility, Sourceror.FP, can generate a commented disassembly of the Apple II's Applesoft BASIC, the source code for which had never been released by Apple, from the customer's own ROM.
called Merlin 64 "an excellent little assembler with many value added features.