Java command language (JACL)

The Java Command Language (JACL) is an interpreter for the script language Tool Command Language( Tcl), which is completely implemented in Java. Tcl is available as open source and is easy to learn due to its simple structure. However, the Java implementation of Tcl does not integrate the associated "toolkit" for programming graphical user interfaces( GUI). JACL is available in version 1.4.1 from 2008.

JACL is used to integrate scripting functionality into an existing Java application. This makes JACL ideal for users who do not want to learn the complex structures of a Java program. However, JACL also defines an Application Programming Interface( API) on both sides, which can be used to access Java from Tcl and vice versa. JACL contains extensive functions that simplify communication between a Java interpreter and a Tcl interpreter.

As advantages of JACL can be mentioned:

• Convenient interface for Java scripting languages,
• Possibility of object-oriented extension by access to Java objects and libraries.

These are opposed by the following disadvantages:

• JACLs do not work in connection with applets,
• Due to the lack of object-oriented suitability of JACL, there is a possibility to extend classes,
• The use of JACL results in low performance.

The Tcl/Java project has the goal of the integration of Tcl and the Java platform. To this end, TclBlend is another way of coupling Java and Tcl, whereby the Tcl interpreter implemented in the C programming language and the Java Virtual Machine( JVM) are connected via the Java Native Interface (JNI). However, since this results in a higher effort with regard to compilation, JACL is the simpler alternative.