shoreman - a shell implementation of the Procfile format
roundup - a unit testing tool for running roundup(5) test plans which are written in any POSIX shell. Each test in a plan is run in it's own isolated sandbox. A test can pass, be ignored, or fail.
shocco - a quick-and-dirty, literate-programming-style documentation generator written for and in POSIX shell.
The best tips & tricks for bash, explained
Sending and Trapping Signals in POSIX shell
Bash arrays: LinuxJournal Greg's wiki
Cram - a functional testing framework for command line applications