What is it?
Tcl/Tk (pronounced “tickle”; the full name is Tool Command
Language/Tool Kit) is a scripting language used in applications
such as automated testing.
Scripting languages offer an ideal way for programmers to extend
their skillset. They can be learned quickly, with free material
from the internet, and they have large, supportive communities
sharing code and tips.
Tcl/Tk is less well known, but possibly more widely used than
Python, Perl and PHP. It can be used to create cross-platform
applications, is easily deployed and very extensible. Experienced
programmers can pick it up and become productive very quickly.
Tk is the graphical user interface tool for Tcl, and is also
used with other scripting languages.
What is it for?
Tcl/Tk is most commonly used for rapid prototyping, scripted
applications, graphical user interfaces, testing and CGI scripting.
The site Tcl.tk says its uses include massively scalable
database-backed websites, the TclHttpd web server, web programming,
desktop GUI applications for Unix, Windows and Mac OS X, and
embedded development. Tcl has extensions to all standard
databases.
Where did it originate?
John Ousterhout began working on Tcl at Berkeley in 1987. In
1994 he joined Sun, where Tcl/Tk was seen as a perfect complement
to Java for scripting and system integration.
How difficult is it to master?
Tcl has a very simple syntax, which is applied in a consistent
way, making it easy to apply once the basics have been picked
up.
Where is it used?
Widely by software and networking equipment suppliers, and by
end-user organisations including Shell, Pixar, various
broadcasters, defence companies and the Hubble space telescope.
What makes it special?
Speed of development, with claims that Tcl can be five to 10
times faster than other languages, particularly for applications
involving GUIs, string handling or integration. The Tk GUI toolkit
is emerging as a de facto standard far beyond the Tcl user
base.
What systems does it run on?
Windows, Macintosh, Linux and most flavours of Unix. The
high-level application programme interfaces means code runs
unchanged on all platforms, with Tcl/Tk taking care of platform
differences.
What’s coming up?
ActiveState is releasing the beta of ActiveTcl 8.5.0.0, an
industry-standard Tcl distribution on AIX, HP-UX, Linux, Mac OSX,
Solaris and Windows. The standard ActiveTcl distribution can be
downloaded free of charge.
Rates of pay
As Tcl is an add-on, pay is dependent on the other skills the
language is used with. The average salary for Unix developers is
£44,000, and the average for C developers is £40,000.
Training
See the Tcl developer site for training. SourceForge has
tutorials, FAQs, links and other resources.
www.tcl.tk.