Shell and C should be fine. To be honest any pure computation should be fine. Your interactive HyperCard stack if you get the right emulators would be ok. MAME, sure. But anything depending on the persistence of networked resources will not work. Other than Phil Greenspun all the endpoints have changed. CGI with no external dependencies or Ajax should work except it got pwned along the line.
Except most likely it wasn't bash shell, or maybe it was, but it was written on an HP-UX and never ported to anything else.
Likewise the C code might eventually be written in K&R C still, make assumptions of byte ordering on the MIPS and memory access semantics of workstation it was originally targeted for, and with luck use SGIPro extensions.
