c++, c++filt, cc (link to gcc), cc1, cc1plus, collect2, cpp, cpp0, g++, gcc, gcov, protoize and unprotoize These are the C compiler. A compiler translates source code in text format to a format that a computer understands. After a source code file is compiled into an object file, a linker will create an executable file from one or more of these compiler generated object files. These are the C++ compiler; the equivalent of cc and gcc etc. c++filt is used to demangle C++ symbols. collect2 assists with the compilation of constructors. cpp pre-processes a source file, such as including the contents of header files into the source file. It's a good idea to not do this manually to save a lot of time. Someone just inserts a line like #include <filename>. The preprocessor inserts the contents of that file into the source file. That's one of the things a preprocessor does. gcov analyzes programs to help create more efficient, faster running code through optimization. protoize converts old-style pre-ANSI functions or definitions to new-style ANSI C prototypes (the default file for looking known ones up is /usr/lib/gcc-lib/<arch>/<version>/SYSCALLS.c.X). unprotoize converts prototypes back to the original old-style pre-ANSI functions, doing a correct job only when they were converted with protoize. libgcc.a, libiberty.a, libstdc++.[a,so] libgcc.a is a run-time support file for gcc. Most of the time, on most machines, libgcc.a is not actually necessary. libiberty is a collection of subroutines used by various GNU programs including getopt, obstack, strerror, strtol and strtoul. libstdc++ is the C++ library. It is used by C++ programs and contains functions that are frequently used in C++ programs. This way the programmer doesn't have to write certain functions (such as writing a string of text to the screen) from scratch every time he creates a program.