There are some significant differences when invoking javac through its native launcher and via its ToolProvider. These differences should be clearly documented.

The following features are only supported by the javac launcher

* The -J option
* The "classpath wildcard" feature

The following features are not supported on the JavaCompiler interface.
* @files
* JDK_JAVAC_OPTIONS (to be verified)
* "information" options, like --help, --help-extra, --version, --full-version

Although not a difference, it should be emphasized that the CLASSPATH env var may be read when using the ToolProvider API