The bastard disassembler is a disassembler written for x86 ELF targets on Linux. Other file formats/CPUs can be 'plugged in'. It has a command-line interface and is meant to be used as a backend or engine. Support for controlling the disassembler via pipes is provided. Note that this disassembler does not rely on libopcodes to do its disassembly. Rather, the 'libi386' plugin is a standard .so that can be reused by other projects.
This interpreter can be used interactively, it can be fed commands via STDIN [just like a scripting interpreter], and it can be communicated with via a pair of FIFOs. Now, on top of this any number of UI front ends can be stacked -- ncurses console front ends, Gtk X front-ends, Tk front ends, etc. It is the reponsibility of the front-ends to display the information obtained by querying the disassembler, supplying syntax highlighting, displaying strings, xrefs, etc; however the disassembler will retain all of this information, do all of the 'brute' processing, and will provide any of the information when requested.