4.4 Tcl

http://www.sunlabs.com/research/tcl/ index.html

Java and Tcl [Ous91] are both being promoted by Sun as web programming languages. Nevertheless, they both occupy quite different niches. Tcl is a high-level scripting language allowing to create small and medium-sized applications quickly and to glue together existing components. It has a simple syntax and almost no structure, which makes it good for scripting. However, Tcl as an interpreted language is not well-suited for very large tasks involving iterative calculations. Java, on the other hand, is a system programming language like C or C++. It is much more structured than Tcl. Java requires a higher initial learning effort, as it is more complex to build applications there, but this structure also makes it easier to build large complex applications. Java is compiled, which results in greater efficiency, and Java supports multi-threading, whereas Tcl does not. Sun envisions a symbiosis between Tcl and Java where Java is used to build new primitives which are then glued together into various applications by Tcl/Tk.

http://www.qualcomm.com/ProdTech/quest/times/ETFall94/ SafeTcl.html

Safe-Tcl has been developed by Nathaniel Borenstein and Marshall T. Rose based on John Ousterhout's Tcl language described in the previous paragraph. The Safe-Tcl extension to Tcl/Tk disables Tcl functions that might cause damage to the downloading environment in a hostile or badly written script.

http://www.cs.dartmouth.edu/~agent

Agent-Tcl adds remote programming capabilities to Tcl similar to the features of Telescript described in the next section. It is currently being developed by Robert Gray in the Agents group at Dartmouth College. The agents migrate from machine to machine using the jump command. Execution resumes on the destination machine at the statement immediately after the jump. Modifications to the Tcl core allow the capture of the complete internal state of an executing script.