The Amazing Awk Assembler (aaa) is a primitive assembler written entirely in awk and sed. It is quite slow, the input syntax is eccentric and rather restricted, and error checking is virtually nonexistent, but it does work. Furthermore it's very easy to adapt to a new machine, provided the machine falls into the generic "8-bit-micro" category.
Releaser is a set of scripts to automate and manage the tasks related to software package releases. It is designed to be modular and to make it easy to both select a particular set of actions associated with releases of a particular project (such as changelog generation, uploading of tarballs, posting announcements to mailing lists), and create new actions that integrate seamlessly into the process. Its status is still somewhat experimental, but the most basic functionality is there.