Anyone who has been using Linux/UNIX for a long time will have to admit that offerings in terms of desktop environments have improved immensely. For those unfamiliar with Linux or UNIX, a desktop environment is a graphical interface (mouse pointer, background, window rendering, etc.) that is completely self-reliant in terms of support programs (file manager, text editor, etc.). If unfamiliar with Linux or UNIX, you might say “What’s the big deal?” The big deal is that most window managers (another form of graphical interface and part of a desktop environment, but that lacks self-reliant applications like its own file manager) do not. There are a variety of desktop environments out there, such as KDE, GNOME, MATE, LXDE and FVWM Crystal, for example. However, I want to focus on the Xfce Desktop Environment and why I believe that it rocks.
Xfce has evolved since its initial incarnation as an open source alternative to the (then) proprietary CDE (Common Desktop Environment) to take on a life of its own. Xfce was originally XFCE (XForms Common Environment, the “X” coming from the “X” in X Window System, the official name of the Linux/UNIX graphical interface system), but now Xfce is no longer an acronym for anything. So, why do I think Xfce is so special?
First of all, unlike desktop environments like KDE or GNOME, Xfce is fairly light on system resources. This means that it will run well on older hardware. This makes it ideal for anyone or any organization that cannot afford the latest cutting-edge hardware. Public schools come to mind here. Another reason why I love Xfce is that it supports a high level of customization. Its appearance and function can be easily modified through context-sensitive menus. This includes such things as appearance, system performance and accessibility to name a few. Xfce can easily look like any graphical interface that you can imagine.
Another feature of Xfce that relates to appearance and that I have come to truly value is panels. Panels, often referred to as docks, are bars that can appear horizontally or vertically on your desktop, providing a place to put things like a main menu launcher, a clock or a quick way to launch frequently used programs. Xfce requires that you have at least one panel. It does not, however, have any requirements as to what you do with that panel. That panel can serve in any capacity that you desire. You can even auto-hide the panel so that it only appears when your mouse pointer hovers over it. The screenshot at right shows what the author has done with his panels. There are three types of panels offered: horizontal, vertical and deskbar (this latter panel is vertically aligned, but the contents are aligned horizontally. This is ideal for wide-screen computing).
This leads to another one of Xfce’s useful features, Panel Plugins. These plugins enhance functionality and provide information about your system and the world around you. Available plugins include ways to track open applications, ways to monitor system resources and a means for keeping informed about time and the weather, Launcher plugins provide a means to quickly launch your favorite programs. There are plugins for switching workspaces, creating desktop sticky notes, monitoring network traffic, monitoring project time, getting screenshots and even quick access to an integrated online dictionary. This list is by no means all-inclusive. If you have a job to do, there’s probably a plugin to help you do it.
Finally, I love Xfce’s ease of use. This is due to a number of things, but simplicity is key. The interface in general is approachable by default. Widgets and menus are where you would expect them to be. The Main Menu is straightforward, reminiscent of what Microsoft Windows looked like before XP. The menu opens providing users with direct access to what they’re looking for, organized by purpose (Communications, Office, etc.). Context menus (opened with a right-click) allow for ready modification of any component. If this isa’t appealing, users can easily change the way Xfce looks and works using these menus.
In closing, if you haven’t tried Xfce, maybe you should. It’s light, simple and effectual. What’s not to like?
Xfce Development Team (2016). Xfce Desktop Environment [computer software]. GNU General Public License.
It is with heavy heart that I report that the Qimo4Kids Project, has ceased. This project developed and promoted Qimo4Kids, an open source educational operating system for children. Based on Xubuntu Linux, Qimo4Kids incorporated the Xfce Desktop Environment with collection of open source educational suites and software. The developers sadly announced via their now defunct Web site and via the Qimo4Kids facebook page that the project had not been updated in several years, due primarily to the fact that other things kept arising that prevented this. C’est la vie. They also felt that the project was not as poignant as it was when first created. This was a fun, engaging OS and the worlds of open source and education are the poorer for its concluding.
Arguably a difficult transition that Windows users undergo when switching to Linux is the lack of video editing software, like Microsoft Movie Maker. Have no fear! Pitivi comes to the rescue. Pitivi (pronounced pee-tee-vee) is an open source video editor for the Linux operating system and built upon the GStreamer multimedia framework.
Upon launch, Pitivi opens a greeting window providing the user with the opportunity to open an existing project or to create a new one. Behind this is the main screen where the film editing/creation takes place. The interface is pleasantly straightforward and intuitive. A menu and toolbar at the top of the screen are referred to as the header bar. Below this are two tabs, or primary tabs, to the left, above a pane. These tabs allow users to toggle between the media library and effects library. To the right are the contextual tabs, which allow users to view clip properties, add transitions and to add titles. To the right of this, is the viewer, through which users can observe their developing creations. The interface for the viewer is the same as for any media player. Below these three panes is the ruler and below that the timeline. This is where videos are placed to be modified.
Media can be added to the media library by either clicking on and dragging the desired file from the file manager window to this pane or by clicking on the Import button above this pane and to the left. When imported, media can then be dragged to and dropped on the timeline. Once a film clip is added, the clip as it will be seen by viewers appears in the viewer. When a user clicks anywhere along the timeline, the viewer jumps to that position. Using the timeline toolbar to the right of the timeline, users can delete selected clips, group clips, ungroup clips, copy, paste and toggle gaps in media. All edits affect the selected clip.
A click of a mouse button (right or left) places the playhead at the desired point on the timeline. This is where splits are inserted. Other tweaks involve being able to control the zoom on the timeline, adding a title, adding special effects and adding transitions. As effects are added to a clip, they are listed in the contextual tab with a checkbox next to each. The checkboxes are checked by default, so, as expected, unchecking one disables it. Effects include, but are by no means limited to, such items as facedetect (detects faces in videos), kaleidoscope and Tunnel (creates a light tunnel effect).
Pitivi is very versatile in terms of file support. Projects may be saved (or rendered which is the term used in Pitivi) in the following formats: AVI, Apple QuickTime, Ogg Vorbis, MP4 and MPEG to name a few. Furthermore, Pitivi offers excellent project management. The term project in Pitivi refers to any film being edited. But users can save their projects at different levels of completion or in different file formats. Many different settings can be adjusted, such as pixel and display aspect ratios, and there is an excellent Undo/Redo utility.
Now that you’ve read about what Pitivi can do, give it a try. Better still, let your students give it a try if you really want to see Pitivi put through its paces. If you’re so inclined, you can also contribute to their fund drive. Such support is always appreciated.
Note: Pitivi is designed to run on the GNOME Desktop Environment. However, all of the author’s screenshots were taken while running Pitivi on the Xfce Desktop Environment upon which it ran without issue.
Pitivi [computer software]. (n.d.). GNU General Public License.
JPitivi quick Start manual. (n.d.) GNU General Public License. Retrieved from http://www.pitivi.org/manual/.
I’ve recently come across a very engaging platform through which children can learn to write computer programs. Little Wizard is an open source application designed to help students in the primary grades learn the concepts that are common in all programming languages, such as variables, loops and conditions. Students can do all this using the mouse. Let’s get up front and personal with Little Wizard.
The interface is WYSIWYG and rather delightful in its use of colorful, engaging images. At the top of the window is a menu bar and below this is a toolbar which, by default, has the Program button already depressed. This is referred to as program view. Below the toolbar is a row of tabs, called the palette. Below this is a row of colorful buttons used for writing computer programs by simply clicking on and dragging program elements represented by the buttons to the program grid below. This is where users write their programs. One really cool feature is that users can easily toggle views of their programs by clicking on buttons on the toolbar. Users can bounce from program view to world view to mixed view. World view presents the world grid which allows users to create and alter the wizard’s world. Mixed view displays both the world grid and the program grid. Integrated tooltips nicely enhance functionality.
So, what kind of programs can you write with Little Wizard? Looking at the tabs in the palette should give you a clue: Wizard, Math, Variables, Conditions and Loops and Other. Each tab has icons, which represent different program elements. Wizard controls functions such as movement of the Little Wizard icon. Math is where you find numbers and their operators. Variables provides the ability to add variables to your program. Conditions and Loops allows for conditions (e.g. if/else statements) and loops (e.g. repeat/until statements) to be placed in a program. Other allows users to assign positions or to prompt for user input. Using these tools, young programmers can make the wizard move, wait for user input or even change his world.
So what happens if you need help getting started? The Little Wizard Web site offers a free tutorial that will guide you through Little Wizard’s interface and to help you learn to use the building blocks of computer programming. Sample programs are provided that give Little Wizard the opportunity to show you what it can do. In no time, users can start developing and bringing to life their own ideas. Now stop reading this and download Little Wizard so you can see what your students will create.
Little Wizard is available for Linux and Microsoft Windows.
Kirillov, K. (n.d.). Little Wizard’s home page: tutorial. GNU General Public License. Retrieved from http://littlewizard.sourceforge.net/tutorial.html.
Kwadrans, M. (n.d.). Little wizard [computer software]. GNU General Public License.
Taking a break from my more traditional topics of STEM and programming, I’d like to put the Arts into the spotlight for a change and talk about Ardour, an open source application that allows users to create audio compositions. Undoubtedly, music teachers out there are familiar with the proprietary, but WYSIWYG software, Accoustica Mixcraft. Ardour is just as WYSIWYG, but, as mentioned above, open source. Let’s take a look at Ardour right now.
Ardour is designed to be suitable for audio engineers, musicians, soundtrack editors and composers, but it should be just as ideal an environment for young composers to create their masterpieces. The interface is very similar to the aforementioned Mixcraft. The Editor Window presents a menu at the top of the screen allowing for ready access to features. Below this, the Transport Menu allows users to navigate (Play, Fast Forward, Loop, Record, etc.) through clips added to the Main Canvas below.
. To the right of the Transport Menu are the Clocks, offering four time formats. Right of the Clocks are the Edit Modes and Cursor Modes controls, which allow users to edit clips. Below this is the aforementioned Main Canvas in which sound and video tracks appear, each with its own track. Each track can then be edited individually. To the left of the Main Canvas is the Editor Mixer, which allows users to control volume and other features using slider controls.
So, what can you do with Ardour? I’d venture to say that you could do just about anything that you could do with Mixcraft. Rather than to compare the two, I’ll focus on Ardour’s features and what can be done with them. First of all, Ardour supports importing of the following audio types: AAIF, BWF, CAF ,FLAC and WAV. In terms of audio exporting, the following formats are supported: AAIF, BWF, CAF, FLAC, Ogg and WAV. Ardour is not just limited to handling sound. Videos can be imported and soundtracks extracted from them. Videos can be displayed frame-by-frame on the Video Timeline for easy editing. Users can add start/stop points to the video as well as blank frames and mix the video with the soundtrack of the current session. An Ardour session can even be run simultaneously on multiple computers.
This all sounds great, but it gets better. There are many plugins available for Ardour that enhance its functionality. These are conveniently handled through the Plugin Manager. Plugins allow users to create various audio or MIDI effects and to generate audio by functioning as “software instruments.” Additionally, although Ardour does not include music/sounds of its own, these can be downloaded from sites like Freesound (see below) and then imported into Ardour.
After reading this, I don’t know why you’re not downloading Ardour right now. Your students may not thank you with words, but their compositions will speak volumes.
Ardour is available for Linux and Apple MacOS.
Thanks to Paul Davis of the Ardour Development Team for permission to use all images included in this article.
Ardour [computer software]. (n.d.). GNU General Public License.
Ardour Manual. (n.d.). GNU General Public License.
Mixcraft 7 vs Ardour -audio editing comparison. (2016). Software Insider: Graphiq, Inc. Retrieved from http://sound-editing.softwareinsider.com/compare/39-169/Acoustica-Mixcraft-7-vs-Ardour.
ExpEYES is a low-cost open source framework of computer hardware and software that provides a means to perform low-cost science experiments using computers. ExpEYES offers formats designed for students from high school on. Let’s take a look at what can be done with ExpEYES.
According to its Web site, ExpEYES is a tool for learning science through exploration and experimentation, It includes integrated an oscilloscope and a signal generator and is powered via USB. ExpEYES offers 12-bit analog resolution, accurate measurements and is physically compact, for easy relocation. The software for ExpEYES is written in Python, an open source programming language. The online manual presents 50 (yes, fifty!) experiments that users can duplicate and, perhaps tha coolest feature of all, others can be easily created and added to the list.
So, from where does this marvel of scientific exploration come? ExpEYES was developed by the PHOENIX project of Inter-University Accelerator Centre (IUAC) of New Delhi. The long-term goal of this project is to make the equipment and methods used in research available to the student community. In science, experiments are performed, data is collected and analyzed. Conclusions drawn. The difference offered by ExpEYEs is the fact that the equipment is affordable.
So, what kind of experiments can a burgeoning scientist perform with ExpEYES? According to the ExpEYES User’s Manual, users can conduct experiments involving electricity, magnetism, electronics, sound, mechanics, optics, heat and computer programming. In terms of electricity, young scientists can perform experiments involving, among many other topics, voltage measurement, water conductivity and AC circuit study. Regarding electricity and magnetism, possible experiments include creating a simple AC generator and making an electromagnet. Some of the other experiments include amplitude and frequency modulation (electronics), sound velocity, using a stroboscope and hardware communication.
As potentially enriching as ExpEYES sounds, it is just one of several open source technology products created as part of the PHOENIX Project. If you’re interested in learning more about this and other opportunities to cultivate the scientists and engineers in your school, you should check out the ExpEYES Web site. Your students will thank you through their creations, if not through their words.
Thanks to Ajith Kumar for his support, the contributions that he provided and for suggested modifications.
ExpEYES is available for Linux and Microsoft Windows. It is available in Canada and the UK.
ExpEYES junior user’s manual: experiments for young engineers and scientists. n.d.). New Delhi: Inter-University Accelerator Centre. GNU General Public License. Retrieved from http://www.iuac.res.in/~elab/expeyes/Documents/eyesj-a4.pdf.
I came across this little gem while perusing the Ubuntu Software Center and decided to give it a shot. Stellarium is an open source, free planetarium that runs right on your computer. To be honest, I was really taken aback by Stellarium’s stunning appearance and visual quality. For one thing, it doesn’t run in a window. It launches into full-screen mode, which beautifully presents the eye-catching graphics. I can discuss this further at another point.
As previously mentioned, Stellarium opens in full screen mode by default. The user finds him or herself looking up at the night sky in the northern hemisphere. Only the major heavenly bodies and cardinal compass points are labeled. The interface is very straightforward. At the bottom of the screen, a panel provides information such as location (Paris, France by default), elevation, Field of View (FOV), Frames Per Second (FPS), date and time. Clicking on a heavenly body brings up information about that body, such as its name, position and distance from Earth. Configuration is handled through two docks/panels called toolbars in the lower left corner. The bottom toolbar, or main toolbar, allows the user to turn visual effects on and off. The side toolbar opens dialog boxes used to configure Stellarium.
So, what does Stellarium have to offer in terms of features? According to the Stellarium Web site, Stellarium includes a default catalog of over 600,000 stars (though additional catalogs containing up to 210 million are available) There are optional connecting lines and/or illustrations (referred to as Constellation Art) that can be toggled to better visualize constellations. Stellarium offers constellations for over 20 cultures and the stories behind those constellations. Views of every planet, and their satellites, are provided. Other features include powerful zoom, multilingual support, time controls, excellent graphics and integrated help.
Arguably, one of Stellarium’s greatest strengths is the level of customization that it offers. First of all, as I mentioned, Paris, France is the default location. Paris is, however, one of hundreds of locations around the world from which users may choose for their session. Additionally, if you’re bored with Earth, you can view the stars from such heavenly bodies as Mars, Saturn or the Moon. One feature that the author thought was pretty cool was being able to toggle the visibility of the ground. Remove the ground and you can view the whole night sky, northern and southern hemispheres, just as if you were in outer space. Other features that can be controlled include equatorial and azumuthal lines, the flow and direction of time and visibility of nebulae. Combine these with the many other features available and you have an incredible platform upon which your students can explore the universe.
Stellarium is available for Linux, Apple MacOS and Microsoft Windows.
Category: User’s guide. (2014). Retrieved from the Stellarium Wiki: http://www.stellarium.org/wiki/index.php/Category:User’s_Guide
Ozark is an object-oriented programming language designed for building software that is readable and reusable. So, what is “object-oriented Programming”? According to TechTarget (2015), object-oriented programming OOP) utilizes a programming language that focuses on objects rather than actions and data rather than logic. In brief, the programmer identifies the objects he or she wants to manipulate and the relationship(s) of these objects, often referred to as data modeling. Each object is categorized and the category determines the type of data assigned to the object. If this sounds confusing, think of a toolbox. Each tool has a specific purpose. Object-oriented programming allows the programmer to define the tools and their purposes.
The philosophy behind Ozark is that of strict code formatting. What this means to users is that there is only one way to do each function. This minimizes error potential. For example, look at a word processor. How many ways are there to perform a task, such as text alignment formatting? At least two methods immediately come to mind. Imagine if there was only one way to do this. You would save much time, as you wouldn’t have to correct mistakes made by invoking the wrong method. Many programming languages work in a similar fashion as there may be more than one way to do something. Choose the wrong one and your program doesn’t work correctly. This scenario is eliminated in Ozark. Strict formatting also means that even if you are unfamiliar with a particular application written in Ozark, you should have little trouble understanding its code.
Ozark is still in its early development stages. In fact, the complier is still under development. However, though you cannot execute programs created in Ozark, you can still write the code, which is great training and practice. For more information about Ozark or how you can help, please check out the Ozone Web Site (link provided below).
All images are from the Ozark Web site and are the property of Finch Software.
Ozark Language – Documentation. (n.d.). San Diego: Finch Software.
What is object-oriented programming? (2015). TechTarget. Retrieved from http://searchsoa.techtarget.com/definition/object-oriented-programming
I’d like to focus on computer programming in this installment. Towards this end, I’d like to take a look at Pharo, a software development environment released under the MIT License (similar to GPL, see link below). Pharo provides a graphical way to utilize the Smalltalk programming language, the programming language used to write Dr. Geo, one of my favorite geometry exploration programs.
First of all, Pharo’s development team refers to Pharo as an “immersive programming environment.” What does this mean? Dictionary.com defines immersive as an adjective “noting or pertaining to digital technology or images that deeply involve one’s senses and may create an altered mental state.” Techopedia defines a programming environment as “a collection of procedures and tools for developing, testing and debugging an application or program.” Another name for such an environment is Integrated Development Environment or IDE. What this means is that Pharo provides a graphical interface for Smalltalk that is so intuitive, full-featured and graceful that it allows you to code without getting in the way.
Before I go further, I’d like to share a few things from Pharo’s mission statement. The Pharo team seeks to provide an accessible and innovative free, open source programming environment. These people strive to keep Pharo small, stable and equipped with excellent tools key for software development. Finally, Pharo seeks to foster a healthy ecosystem of contributors who strive to maintain and enhance this application.
Smalltalk is an object-oriented programming language, which, in layman’s terms means that it focuses more on objects and data rather than on commands, or actions, and logic. Keeping this in mind, Pharo is designed to be very straightforward to use and to provide prompt feedback. Pharo also includes an IDE (Integrated Development Environment), from which it draws its simplicity. Furthermore, Pharo offers a high level of diversity through a large library and a set of external applications. Pharo also includes strong support for business use in the form of organizations, such as the Pharo Industrial Consortium and an association of users, the Pharo Association.
I’d like to take a look at Pharo’s interface as this is key to Pharo’s ease of use. How often have you launched a new program with some trepidation, wondering with what will I be presented? How intuitive will the interface be? How long will it take me to figure out how to make this thing do what I need it to do? Arguably, Pharo’s interface, or lack thereof, is not just one of its strengths. It’s also aesthetically appealing. No need for a menu bar or tool bar, as Pharo relies on context-sensitive menus for its functionally. Simply click in the main window to open the World Menu, which is a general menu, from which you can select Workspace. A Workspace is like an artist’s sketchpad upon which you create your application. Once a Workspace has been opened, you can use contextual menus to perform desired tasks.
So, what’s the best thing about Pharo? It could be that it is free to download. It could be the number of free books about Pharo available online. It could also be the extensive support community. I leave it to you, the reader, to download and install Pharo. Then start using it and find out for yourself what you think is the best thing about Pharo.
Pharo is available for Microsoft Windows, Apple MacOS and GNU/Linux.
Thanks to the people at Pharo for permission to use their screenshots for this article.
Black, A.P., Ducasse, S., Nierstrasz, O., Pollet, D., Cassou, D. & Denker, M. (2009). Pharo by example. Switzerland: Square Bracket Associates. Retrieved http://pharobyexample.org/versions/PBE1-2009-10-28.pdf
Immersive. (n.d.). In Dictionary.com. Retrieved from http://dictionary.reference.com/browse/immersive?s=t
Pharo [computer software]. (n.d.). GNU General Public License.
programming environment. (n.d.). Techopedia. Retrieved from https://www.techopedia.com/definition/16376/development-environment