make3_80-sh is a compatibility layer for GNU make 3.80. Starting with 3.81, GNU make treats backslash newlines in commands in a POSIX-compatible way. This breaks older Makefiles. make3_80-sh is a compatibility layer to use old Makefiles with GNU make 3.81. It also aids migration of such Makefiles.
MakeModules (mamo) consists of a collection of Makefile snippets called modules. Each module defines features for a single or some related common tasks. For instance, the module "C" defines features for generating object files from C sources, the module "Pod" defines features to generate documentation from pod sources, and the module "Install" defines features for installing files in various ways locally or on a remote host. The important module "Subdirectory" defines recursive operation in a directory tree. In no way are tasks limited to programming. For instance, mamo can be used to maintain a Web site.