COFF

[citation needed] As development of Unix-like systems continued both inside and outside AT&T, different solutions to these and other issues emerged.

All real world implementations of COFF were necessarily violations of the standard as a result.

IBM used the XCOFF format in AIX; DEC, SGI and others used ECOFF; and numerous SysV ports and tool chains targeting embedded development each created their own, incompatible, variations.

[3] COFF's main improvement over a.out was the introduction of multiple named sections in the object file.

Each symbol table entry includes a name, storage class, type, value and section number.

Note that COFF was not capable of representing line numbers or debugging symbols for included source as with header files rendering the COFF debugging information virtually useless without incompatible extensions.

Dates occurring after 19 January 2038 cannot be stored in this format, resulting in an instance of the year 2038 problem.