The main idea is to create a pseudo-shell that runs on any kind of device, from a smartphone to a normal pc.
Jbash can execute built-in commands and external program, export variables, evaluate expressions using a dynamic scope.
jBash is wrote using JavaCC so there is a javacc code implementation. It's released under the GNU GPL license.
(in the image you can see jBash running in a UNIX shell, but whereas it's wrote in Java so it can runs on any O.S. and architecture).
Links about jBash project: