Emu8086 is not available for Linux but there are a few alternatives that runs on Linux with similar functionality. The best Linux alternative is PCem, which is both free and Open Source. If that doesn't suit you, our users have ranked five alternatives to Emu8086 and three of them are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to Emu8086 are NASM (Free, Open Source) and flat assembler (Free, Open Source).
The Netwide Assembler, NASM, is an 80x86 and x86-64 assembler designed for portability and modularity. It supports a range of object file formats, including Linux and *BSD a.out, ELF, COFF, Mach-O, Microsoft 16-bit OBJ, Win32 and Win64. It will also output plain binary files.