Versatile Commodore Emulator
VICE is an emulator collection which emulates the C64, the C64-DTV, the C128, the VIC20, practically all PET models, the PLUS4 and the CBM-II (aka C610). It runs on Unix, MS-DOS, Win32, OS/2, Acorn RISC OS, BeOS, QNX 6.x, Amiga, GP2X or Mac OS X machines.
Portable Figure Out system properties
pofig - portable shell script for probing base system properties: OS, OS version, kernel version, distro, distro version, architecture. It detects: 19 operating systems, 11 major linux distros, 13 CPU types. See wiki for more information and examples.
Command validation tool
cmdok checks that specified commands are OK. If command is OK than it exists in PATH and can be run. It is a simple, small and portable Bash script. It is useful in software packages that want to check that some commands exist before trying to run them. See wiki for more information and examples.
C/C++ system probe, test and automation toolkit
cstem is a portable toolkit for probing and testing C/C++ system. It consist of 4 scripts: cprobe, cltest, cppdef, mkdep. cstem scripts can be used standalone or as part of software build systems. All scripts are portable and have no dependencies. See wiki for more information and examples.