Overview report on the Tcl/Tk GSoC projects for 2009

In this paper we present an early prototype of a wiki-based SCORM authoring platform, which was developed in the context of the Google Summer of Code 2009. We based our implementation upon OpenACS's existing wiki application XoWiki and tried to realize the concepts of SCORM (e.g. organizations) using existing implementations (e.g. the categories package).

Report on Google Summer of Code project to Get Jacl to the Tcl 8.4 compilance level and make Jacl more popular again.

Presentation Slides for paper

This paper is Sean's attempt to put together the "Tcl W" of writing code for TclOO. Like everything else Tcl, it's not about tab spacing and pascalNotation vs. underbars_uberalles. It's about how not to hang yourself with some of the rope that the notation provides.

This paper looks at the state of Tcl's new object system, TclOO, looking at the forces that lead to its development and the development process itself. The paper then focuses on the current status of TclOO, especially its interest- ing features that make it well-suited to being a foundational Tcl object system, followed by a look at its actual performance and some of the uses to which it has already been put. Finally, the paper looks ahead to some of the areas where work may well be focused in the future.

Recent work on the Extended Object Tcl (XOTcl) was geared towards the orthogonality, the ease of use, the productiveness, and the tailorability of the language. The result is an innovative object-oriented language framework which serves for developing a family of object- oriented Tcl dialects. In this work-in-progress report, we map the background and history of advanced language constructs (i.e., mixin classes, filters, method delegation) and their continued refinement (i.e., transitive mixins, mixin and filter guards). We present the infrastructure for creating derivative Tcl OO dialects (i.e., creating object systems and their structural relations, assembling base object behavior). A canonical model and infrastructure of parametrization of commands, methods, and objects is presented. Important steps of internal re-designing and refactoring (callstack and object life-time management) are discussed. Execution time and call throughput measurements for basic object life-time and method dispatch scenarios are reported, exhibiting substantial improvements over the XOTcl 1.6.x branch and TclOO 0.6.

Tcl/Tk safe interpreters provide a secure environment for running arbitrary untrusted code. We have developed Web clients in Tcl/Tk that are optimized for running Tcl/Tk applications. We have also developed server-side tools that permit collaborative development of Tcl/Tk code in a Wiki-like environment, but optimized for code rather than text. We combine the advantages of the browser plugin and the Wiki, with added features such as an enhanced security policy, local caching, and remote storage of personal files. The clients can be compared with Adobe Air or Microsoft Silverlight, but are better oriented to sharing code because by default the client receives the full Tcl/Tk source code.

Stargus is an ongoing project to develop a compact, portable and scaleable virtual computing environment, based on the Tcl/Tk platform. This paper introduces two key Stargus technologies aimed at supporting Cloud Computing: secure authentication via BetterID and shared storage via Mockingbird. These technologies are aimed at achieving scaleability and security by leveraging Cloud Computing while retaining the flexibility and productivity of the Tcl language and associated technologies.

This paper discusses how a GUI required handling multiple datasets at the same time and providing the user with design and debug information for all the datasets currently open, was having problems in switching between different datasets and different views of a same dataset, due to it being written primarily in Tcl. The paper further describes how the GUI is modified using [incr Tcl] to solve these problems by benefiting from the object oriented concepts built in [incr Tcl]. This paper describes how [incr Tcl] is used by ways of code examples. The paper finally concludes mentioning the benefits achieved by this exercise and also provides recommendations on how to avoid the pitfalls in using Tcl and how they can be easily avoided by using [incr Tcl].

Over the past 10 years the Modelsim GUI, written in Tcl/Tk, has grown from a simple user interface with three panes to an elaborate interface comprised of over 50 distinct windows. The Modelsim GUI architecture, while sufficient at the time of creation, began to crumble under the weight of so many windows. This paper will explore the issues that occurred as the window count grew and describe the approach taken to resolve these issues.

CVXT is a Verification Engine from Comit that dates back to the early 90s. It is primarily an control and event based interface between a hardware language software simulator and tcl. This paper is about the Tcl and software side of the tool, the challenges it faced and how coroutines helped.

Presentation slides for CVXT paper

The AnatLab system provides and interactive Web environment for exploring human anatomy, including the locations, identies, relationships and extents of anatomical structures, as well as associated textual information. An early version of AnatLab was demonstrated at Tcl2008. This paper goes beyond that to describe a number of the Tcl-based technologies used to create AnatLab

Tcl/Tk-based whiteboard presentation tool with unique functionalities: Audience can participate in the presentation. Networked. Enables quick construction of complex objects r displaying during presentation.

Text to accompany slides above.

Powerpoint version of presentation slides

We present a unique Tcl/Tk-based whiteboard system that facilitates discussions among multiple participants located at remote sites as well as in classroom or conferenceroom setups. One of its uniquenesses is its capability to convert handwritten complex-structured math/scientific symbols to clean custom-font-based presentations. Another uniqueness is that it enables the user to easily create dynamic discussion tools incorporating various widgets instantly during a discussion, and send them to the whiteboard server for display and manipulation. The above features can be easily augmented to various domains of discussion by adding more Tcl scripts and/or C modules. All of these unique capabilities are made possible by Tcl's easy mergeability with C and its superb scripting characteristics.

This paper describes the history of the reflected and transformed channels exposed at the script level in Tcl 8.5 and higher, provides insight into their implementation, and demonstrates various applications of this feature.

Eagle (Extensible Adaptable Generalized Logic Engine) is an implementation of the Tcl scripting language for the Common Language Runtime (CLR). It is designed to be a universal scripting solution for any CLR-based language.

Slides for paper above.

Slides for paper above.

Introduction to Fossil, a Distributed version control system with builtin bug tracking, wiki and web interface based on Sqlite and Tcl

Introduces Sqlite and describes the integration of the database tool and Tcl.

The safety of dikes in the Netherlands, located in the delta of the rivers Rhine, Meuse and Scheldt, has been the subject of debate for more than ten years. The safety (or flood risk) of a particular area may depend on the safety of other areas. This is referred to as effects of river system behaviour on flood risk (quantified as the estimated number of casualties and economic damage). In the Netherlands, such effects are found to be important for the understanding and evaluation of flood risks.

PDF Slides for Flood Risk talk

PowerPoint Slides for Flood Risk talk

Gridgen is meshing software used by engineers and scientists worldwide since 1984 to reliably generate high quality grids for engineering analysis. Gridgen Glyph, which is Gridgen's Tcl- based scripting language, provides full access to the functionalities available interactively in Gridgen. It allows users to extend Gridgen's functions as well as develop specialized meshing applications. This paper shows how a new Gridgen capability, automated block topology change, is developed through a script using Glyph, Tcl and Tk. This feature changes grid topologies in a matter of seconds while interactively changing grid topologies can require hours of a user's time.

Presentation slides for above paper

Suggestions (and code) for improvements to Tkcon