Where Is Tcl Hiding?
by Andreas Kupries

Andreas Kupries, February 15, 2010

Where is Tcl hidingIn basements, gadgets, and embedded in a multitude of applications, where it is silently humming along, working for many people without them being aware of its presence.

For example, as Perl is often called the "duct tape of the Internet", Tcl can be seen as its foundation, running quietly in numerous Cisco routers and other network management tools from companies like Muonics, ByteSphere and iDirect, ensuring that your bytes get where they belong.

Further, consider the multitude of chips in our computers and gadgets. Many of them developed using eCAD systems provided by Mentor Graphics and others. Tcl is embedded into these for automation, customization, GUIs, and testing, ensuring that all these gadgets work as intended.

Have you gone to the movies lately? Several visual effects companies provide products which have Tcl inside for control, automation, flexibility. Not just for niche movies, but block busters as well. The Orc armies in the Lord Of The Rings trilogy were, for example, animated by Massive Software's crowd-simulation and 3d animation tool, where Tcl is used to automate large repetitive tasks.

Tcl is often mistakenly considered a niche language, but it pops up in a surprisingly large variety of niches. It's one of the best kept secrets behind the success of many applications and devices.

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Andreas Kupries is a senior Tcl developer at ActiveState where his focus is the ActiveTcl distribution. He also works on the Tcl Dev Kit component of ASPN Tcl. Andreas is a member of the Tcl Core Team. He's the Tcllib release manager and has authored more than 25 Tcl modules and extensions! He has a Master in Computer Science from the RWTH Aachen.


7 comments for Where Is Tcl Hiding?

Any project to use Tcl as a development platform on the iPhone ?


What I am aware of is

which has some information halfway down the page.


Stefane - The key issue there is the legal restrictions Apple imposes in the iPhone SDK EULA that prohibits apps that run interpreted code or arbitrary scripts. This obvious limits providing any dynamic language environments on the iPhone "as is". It would be possible to have an app that uses Tcl wholly embedded, and indeed Tcl does compile for the ARM system that the iPhone is based on. However, I'm not currently aware of any deployed usage of Tcl in that manner. It would then have to be clearly advertised, and people don't generally discuss underlying code.


On a side note, if you are interested in Android scripting, you can find some info on that at



from what I and other people understand, Apple's restriction are only on dynamic code that can be downloaded form the Internet. It seems you can use a scripting language to generate a standalone executable.

There are a couple of projects involving Lua (iPhone Wax and Corona) and Javascript (Appcelerator Titanium), which have help some people publish successful apps on the app store, but OTOH no Tcl nor Python.


[...] First of all, if you aren’t familiar with Tcl it’s “originally from “Tool Command Language”, but conventionally rendered as Tcl is a scripting language created by John Ousterhout”. I encourage you to test it and also if you are interested read Where’s Tcl hiding?. [...]