Classfile Reader & Writer is a Java package that makes it easy to read and write Java class files. It does not provide any help with displaying the contents of a class file (besides debug output) or disassembe the byte codes, but can read "obfuscated" class files such as those generated by Crema.
The Java Binary Enhancement Tool (JBET) is a general Java program analysis and manipulation tool. Existing class files can be disassembled, eassembled, or edited programmatically through the JBET API. JBET can also be used to create new Java class files from scratch. It uses a convenient internal representation of all the contents of Java binary (.class) files, allowing the user to edit the classes easily, in a structured manner.
asfpga is an assembler written for use in FPGA design. It can be easily modified for a particular instruction set. The ultimate goal of this software is to allow a FPGA designer to easily write assembly code for a custom instruction set. The current version allows you to create a listing file, a memory dump file which can be used in debugging HDL code using $readmemh() or equivalent routine, and a binary file which can be used to program an EPROM.
Linux Debug is a functional clone of the old DOS debug.com for x86 linux. Functions include the ability to alter/examine memory and registers, set/clear breakpoints, step into and trace over, symmetric symbolic disassembler, and symbolic assembler. It has a simplified UI, and can work with bin and elf format files. Symbolic functions work only if debug symbols available in the file header. It features a NASM-compatible syntax for both disassembler and single line assembler.