We hope you've found this tutorial instructive! We think Tcl and Java are a brilliant combination, and that the Tcl Blend and Jacl products offer a comprehensive -- if a little immature -- way of combining these two languages. Now, when we say "immature," we don't mean there's anything wrong with them, but it is, after all, a 1.0 release.

During the tutorial we glossed over the occasional compatibility problem. Here is our summary of what works with what:

Tcl 8.0 Tcl 8.1 [incr Tcl] 3.0 Jacl
JDK 1.1 X - X X
JDK 1.2 ? - ? X
Microsoft VM - - - X

X = Works
? = Works with the Tcl Blend 1.0up2 patch
- = Doesn't work

What of the future? According to the Tcl Blend/Jacl download page, 1.0 is a "final release." This does not mean that it has been abandoned, though, just put on hold while Scriptics gets established with their flagship TclPro product. According to Scriptics:

"Scriptics has a strong commitment to Tcl/Java integration. Initially our preferred method is Tcl Blend, which provides the full feature set of Tcl by integrating the existing implementation with the Java Virtual Machine. Jacl is suited for pure-Java environments, but it is a big project to provide all the current functionality of Tcl. Our plans include enhancing Jacl, but at this date we are not sure of the rate at which progress will be made."
If you have specific questions about the Jacl and Tcl Blend products, you can send mail to You can also send mail to Ray Johnson, the Tcl Blend/Jacl product manager, with your opinions and suggestions on these products. Note also that Scriptics is tracking bugs in Tcl Blend and Jacl, and you can send bug reports to and the comp.lang.tcl newsgroup.

For us, we're planning to release a completely new version of Ptolemy in the fall, which relies on Tcl Blend to "glue" together its user interface (written in [incr Tcl]) and its simulation engine (written in Java).

And of course, we'd like to hear your comments on this tutorial. If you are planning on attending the tutorial in San Diego in September, be sure to send us email about what you think we should be presenting there.


Our beta testers were invaluable in helping us find problems and generally improving this tutorial: Ron Galicia, Xiaojun Liu, Lukito Muliadi, and Neil Smyth. Ray Johnson of Scriptics provided us with the information on Tcl Blend and Jacl support and future development.