BEYE (Binary EYE) is a free, portable, advanced file viewer with built-in editor for binary, hexadecimal and disassembler modes. It contains a highlight AVR/Java/i86-AMD64/ARM-XScale/PPC-64 and other disassembler, full preview of MZ,NE,PE,ELF and other.
An executable Jar file contains both a Swing-based editor with syntax-highlighting, online help, example generator etc. for the "httest" tool (https://sourceforge.net/projects/htt/), as well as a Java API wrapper for writing JUnit tests with "httest".