Monthly Archives: June 2007

All about Windows Presentation Foundation

Everything you want to know on Windows Presentation Foundation, the technology inside .NET 3.x, now in the WPF encyclopedia:

created and maintained by Actipro Software, but you can add your favorite links.

What is is a free community resource that was created to provide an organized one-stop resource guide for Windows Presentation Foundation (WPF) developers.

There is a lot of great WPF-related information out on the web that developers have posted. However the problem used to be finding it. The resource guide solves this problem by providing a categorized list of links to various articles, blog posts, tools, and other resources throughout the web.

While the resource guide is updated by Actipro almost daily, we encourage you to add your own links as well. The resource guide currently contains 419 resource links.

Visit this site often or subscribe to the RSS newsfeed to keep on top of the latest WPF resources on the Internet.

Some categories:

Books, Tutorials and Help

Sample WPF Applications

Essential Tools

WPF Blogs

WPF Sample Code

Thanks to Ezequiel Jadib: he was the source of this link.

Angel “Java” Lopez

Installing Squeak

In the last century, sometimes I was studying Squeak. Now, in these days I have returned to visit it, and wanted to write a simple, introductory article, on its easy installation.

Squeak is an open source implementation of Smalltalk, that has been developed for years. The internal implementation of its virtual machine is interesting, to a great extent written in Smalltalk, with tools to produce its own virtual machine.

Like in other implementations, one needs to install the virtual machine of the operating system that will use. In this article, we will install a version (the 3,9) for Windows. Also we will need an image, a file with the state of the active instances. Smalltalk has been characterized from always, by being able to write and to raise an image, a species of “snapshot” of the state of the system.

The page of Squeak is

For somebody not warned of the existence of virtual machines and images, it is a little confused explanation of its installation:

because there are several options. For example, to lower the versions from

But there is multitude of archives. The one that we are going to use is a file .zip that contains the virtual machine for Windows and image 3,9 (at the moment already there is a developing image 3,10), directly from:

This file contains:

We see a Squeak.exe, that it is the feasible virtual machine. The SqueakV39.sources file is of text, of more than 4 megas of size. It contains the source code of the classes that compose this version. The file Squeak3.9-end-7067.image is the image, “snapshot” that contains the instances of this system.

We can expand the content of this .zip in a directory, and make double click on the feasible one of the virtual machine Squeak.exe. Automatically it detects the image. Alternatively, we could drag from the Explorer de Windows the file image on the file .exe. It appears our first welcome to the Squeak world:

All within this window, is created by the own Squeak. Following the tradition of the original Smalltalk, the graphical aspect, the controls, windows, and others “widgets” are drawn by the own system. The appearance of this window and its contents, then, is independent of the operating system.

In the right lapel titled tools, we found a series of tools. Raising the classic one “to browser” of Smalltalk, we found:

The four superior lists, show, in sequence:

  • categories of classes
  • classes of the selected category
  • categories of methods (of instance or class)
  • methods
  • In the screen capture it appears the classic Object, of Kernel-Objects.

    If you have interest on the virtual machine, can visit

    He is interesting to see the instructions to produce a virtual machine, in Win32:

    Well, for today, enough. I hope that it serves to you, as an start in the use of this implementation of Smalltalk.

    Angel “Java” Lopez

    Learning AJAX

    A month ago, I gave an speech about AJAX, at Club de Programadores, here, in Buenos Aires, Argentina. I published the examples, presentation (in spanish) and resources that I used to prepare the speech. I hope that they will be useful as an introduction to AJAX:

    Source: Adaptive Software

    The initial post written by Jesse James Garret, from Adaptive creating the term AJAX, and explainint it:

    Ajax: A New Approach to Web Applications

    More about Garret at: (his book about The Elements of User Experience)

    Sites about AJAX

    Technologies related to AJAX

    Standard ECMA JavaScript
    The XMLHttpRequest Object

    JavaScript Libraries





    Yahoo User Interface Library

    PHP Libraries


    Ejemplo en


    Java Libraries

    Google Web Toolkit

    AjaxTags – AjaxTags Usage
    AjaxTags – AjaxTags Quick Start


    Dynamic Faces


    .NET Libraries

    ASP.NET Ajax (Microsoft version for Net 2.x)


    During the speech, I search some chat implementations using Ajax:

    I visited some websites with AJAX:

    My links about AJAX:

    I read the excelent book from Francisco Minera, MP Ediciones:

    An alternative, the new Microsoft baby, Silverlight:
    Moonlight – Mono

    Examples from the speech, presentation, at

    Angel “Java” Lopez