JExel is a Java based expression language that provides a non-compiled scripting language parser which can be useful in many different applications.
JExel can handle most basic mathematical and string expressions with the built in operator set fairly easily.
An ideal usage would be allowing a user base access to a limited set of commands/operators but prevent them from causing any harm.
You can specify your own symbols/functions and/or remove the included base level operators. JExel also supports variable resolution through the use of a resolver.
Due to requests, if the GPL v2 license is not compatible with the software (closed source), then there is an alternate paid license available. Also, the developer will provide paid support if needed.
Detailed instructions on how to install and use the JExel utility on your Mac are available HERE.
JExel is cross-platform utility and can be used on any operating system that comes with Java support (e.g. Mac OS X, Windows, Linux).