Commons-launcher eliminates the need for a batch or shell script to launch a java class. some situations where elimination of a batch or shell script may be desirable are:

* you want to avoid having to determining where certain application
paths are e.g. your application's home directory, etc. determining this
dynamically in a windows batch scripts is very tricky on some versions
of windows or when softlinks are used on unix platforms.
* you want to avoid having to handle native file and path separators
or native path quoting issues.
* you need to enforce certain system properties
e.g. java.endorsed.dirs when running with jdk 1.4.
* you want to allow users to pass in custom jvm arguments or system
properties without having to parse and reorder arguments in your
script. this can be tricky and/or messy in batch and shell scripts.
* you want to bootstrap system properties from a configuration file
instead hard-coding them in your batch and shell scripts.
* you want to provide localized error messages which is very tricky
to do in batch and shell scripts.