JShell is a UNIX-like shell written in Java, and intended primarily for working with Java programs. It can be used in conjunction with any JDK 1.1.x JVM. The reason for writing JShell was to overcome the difficulties in working with Java on Psion's 5mx.
JShell's features include:
Here are some examples of what you can do with JShell.
Here is more complete documentation.
If you haven't yet gotten Java running on your 5mx, check out John Davies' web site on the topic.
Follow one of these links to download JShell:
JShell is an open-source project. The software is protected by the GNU General Public License. If you want to work on JShell, here is the source.
The current version of JShell is 0.2. Here is the version history.