For this reason, I decided to dedicate one minute in writing “yet another text to md5 converter“, which I can use in my own server!

Nothing special, just a few lines of PHP code, ut prosim!

<?php
echo '
<h1>Text2MD5 super simple converter</h1>
<p>Type a word or a sentence below:</p>
<form method="get">
 <input name="string" type="text" id="string" />    
 <input type="submit" value="Convert to MD5" />
</form>';

if (isset($_GET['string'])) {    
$str = $_GET['string'];
echo '<p>The MD5 hash of <strong>'.$str.'
</strong> corresponds to:<br /><strong>'.md5($str).'
</strong></p>';
}
?>

Download md5-convert.php – Try it online

“Free software means software that respects user’s freedom. It does not mean zero price software, in fact it’s not directly about money at all, it’s about freedom, so think of free speech, not free beer [...] The software that’s available to the public, but not free software, is called proprietary software or non-free software or user subjugating software, because it keeps the users divided and helpless; divided because each one is forbidden to share, and helpless because the users don’t have the source code so they can’t change the software, they can’t even verify what it does. Free software develops in a kind of democratic society under the control of its users, proprietary software gives the developer power over the user [...] its distribution system is a system for subjugating people, for exercising power over people; and that makes it fundamentally unethical.”

Stallman attraverso la ricorrente esortazione ad intendere il termine free come “libertà di parola” piuttosto che “birra gratis”, chiarisce la valenza semantica di questo vocabolo che, nella lingua inglese, potrebbe dare adito ad incomprensioni; la libertà nel software non ne implica la gratuità (anche se nella maggior parte dei casi il software libero è pure gratuito).
Egli definisce quattro libertà che devono essere rispettate perché un software possa essere considerato “libero”:

“To understand free software you need to understand what the freedoms are: the definition of free software is that the user has four specific freedoms, freedoms that every user of software always should have. Freedom zero is the freedom to run the program as you wish, freedom one is the freedom to help yourself, in other words the freedom to study the source code of the program and then change it to do what you wish. Freedom two is the freedom to help your neighbor; that’s the freedom to make copies and distribute to others, and freedom three is the freedom to help your community, that’s the freedom to publish modified versions so others can get the benefit of your contribution. These four freedom are all essential; in order to be free software the program must give you all of these freedoms.”

Stallman nel 1989 sintetizzò queste libertà in una licenza, la GNU General Public License (GPL). Il software tutelato da tale licenza può essere liberamente utilizzato, modificato, copiato e distribuito; inoltre chi rilascia software secondo questi termini deve distribuirne il codice sorgente. Infine chiunque apporti aggiunte o miglioramenti a programmi rilasciati mediante GPL è vincolato a rendere libere le proprie modifiche.
La General Public License è scritta con un linguaggio giuridico e possiede una valenza legale, poiché registrata dalla Free Software Foundation, che ne detiene il copyright:

“Preamble
The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software–to make sure the software is free for all its users. [...] Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it. For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.[...]”

L’autore di un software ne detiene la paternità intellettuale, ed è un suo diritto optare per la tutela del proprio lavoro attraverso una licenza che permetta di riprodurlo, utilizzarlo e ridistribuirlo, vincolando chiunque lo modifichi a fare lo stesso.
L’idea geniale che sta alla base della GPL (e di altre licenze promosse dalla FSF) consiste proprio nello sfruttamento della stessa legge sul copyright per istituzionalizzare legalmente il copyleft.

___

Questo articolo è tratto dalla mia Tesi di Laurea:

Alberto Betella, “Open Source, Free Software e Podcasting: l’esperienza di Pluriverisadio”, Università degli Studi di Bergamo, A.A. 2005/2006.

"Les Animaux du Futur"

Futuroscope è un parco divertimenti che si trova a Poitiers in Francia, a circa 90 minuti da Parigi. Fin dalla sua apertura nel 1987 questo parco si è costantemente rinnovato adottando le più recenti tecnologie per le proprie attrazioni. Attualmente ospita 20 padiglioni dove è possibile attraversare la via lattea, scoprire i misteri del Nilo, danzare attraverso delle braccia meccaniche…

Nell’aprile 2008 il parco ha inaugurato una nuova attrazione chiamata Les Animaux du Futur (gli animali del futuro), si basa sul documentario “The future is wild”, una co-produzione canadese e tedesca trasmessa in tre episodi da Discovery Channel dove alcuni scienziati immaginano nuove specie di animali in un futuro dove la razza umana sarà estinta. Nonostante questa attrazione sia pensata principalmente per i più piccoli (vi è pure un progetto educativo alla base), anche gli adulti possono senz’altro divertirsi ;-)

Questa attrazione utilizza largamente la tecnologia dell’augmented reality (realtà aumentata) e consiste in un dark ride (ovvero un percorso al buio, come ad esempio i tunnel dell’orrore nei luna park). I visitatori salgono su un veicolo che si trova su una piattaforma mobile e viaggiano attraverso quattro zone (un freddo e secco deserto, la valle paludosa, l’oceano e la foresta pluviale); utilizzando una sorta di binocolo ed uno speciale braccialetto, essi possono vedere all’interno del paesaggio gli animali del futuro, animati in 3D, e possono interagire con loro (toccandoli, offrendo loro cibo, etc…).

La realtà aumentata permette di sovrapporre all’ambiente reale una realtà fittizia e virtuale. A differenza della realtà virtuale, dove si ha un’immersione totale, la realtà aumentata permette di rimanere connessi al “mondo reale” e mantenere un contatto con l’ambiente circostante.

L’augmented reality può essere sperimentata anche attraverso periferiche comuni e diffuse: è sufficiente avere un computer e una webcam (alcune grandi aziende hanno già sperimentato nuove forme di advertising attraverso queste tecnologie).

Il sito ufficiale dell’attrazione Les Animaux du Futur offre due software gratuiti che permettono di provare la tecnologia della realtà aumentata: è sufficiente scaricarli (nel sito sono indicati come Expérience 2008 e 2009) ed installarli nel proprio computer.

Una piovra in testa con la "realtà aumentata"!

Il primo software richiede la stampa di 4 figurine che, mostrate alla webcam, faranno apparire nello schermo i modelli 3D degli animali che potremo osservare da ogni angolazione (utilizzando due figurine contemporaneamente i due animali interagiranno tra loro). Il secondo software, ovvero la versione 2009, utilizza invece una tecnologia di riconoscimento facciale e permette di “incollare” una futuristica piovra sulla nostra testa, muovendoci e avvicinandoci allo schermo, potremo vederla da prospettive differenti… attenzione a non fare movimenti bruschi però, l’animale si spaventa e sparisce!

Da provare dunque…

I due succitati software sono purtroppo disponibili solo per Windows, tuttavia fanno largo uso di librerie ed engine open source rilasciati sotto licenza GNU/GPL, come Ogre (per gestire i modelli 3D), ARToolKit (per il tracking) e DSVideoLib (grabbing del video).

The "Flashlight" effect

OmniDazzle is a piece of software for MAC OS X which provides a set of fun and useful enhancements that help you highlight certain areas of your screen, create visual effects, and track the location of your mouse pointer.

It’s easy to use and it features several effects, such as a flashlight or nice footprints which follow your pointer: these may give a creative touch to your slide presentations and can be useful while recording screencasts…

OmniDazzle is free and can be downloaded from the official web page.

Podcast Generator is free web based podcast publishing script written in PHP: users can upload media files (audio-video) via a web form along with episode information and automatically create podcast w3c-compliant feed including iTunes specific tags.

Podcast Generator is an open source web based software I developed as part of my final degree project in 2007 and I am still maintaining.

To give a look at Podcast Generator, visit the official website: http://podcastgen.sourceforge.net

FileZilla, the popular open source FTP and SFTP client for Windows, has been completely re-written and now is able to run on every major platform, including Linux, Mac OS X and *BSD.

The new cross-platform release of Filezilla (Version 3) will be available officially in a few weeks; in the meanwhile you can already download the Beta version from Sourceforge.

.DS_store are hidden files Mac OS X creates into every folder in order to save non-vital appearance information such as windows position, background and file comments.
These files are generated automatically and are almost invisible to Mac OS X users, anyway, it would be a good idea to delete them if you are going to burn a CD or create a compressed file to share with someone who may adopt another OS, as .DS_store files can result superfluous and annoying.
DS_Store Cleaner is a small piece of software for Mac OS X (Mac OS X 10.3 or later is required) which can help you removing swiftly all .DS_Store files present in a folder and in its sub-folders and can be very useful if you share your compressed archives, CDs or memory sticks: just drag the folder you wish to clean into the application icon and automatically clean it. An alert box will notify about the number of .DS_Store files deleted.
DS_Store Cleaner is freeware and available also for Windows.

Today during the WWDC07 Apple announced that Safari 3 will be released also for Windows platform.

A beta version is already available here:
http://www.apple.com/safari/

According to Apple, Safari is 2 times faster than Internet Explorer 7 and up to 1.6 times faster than Mozilla Firefox.

I downloaded the beta version of Safari and installed it on Windows XP: the installation went smoothly but the browser gave a non critical error on starting. It’s really fast but I experienced some characters and pages rendering issues.
It’s still a beta version of course, but in my opinion the premises are good: waiting for a stable Windows release.

Multiple Internet ExplorerS

Here is a useful tip for web designers and developers who want to test their website with different versions of Internet Explorer.

As a web designer you’ll have to test your website with multiple browsers in order to check the correct behavior of your pages on different platforms.
Whether you like Internet Explorer or not, you’ll have to carefully test your new pages with this browser, which sucks doesn’t respect many international web standards, but unfortunately is still the most popular among internet surfers.

If you update your copy of Windows XP, IE 6 will be replaced with the new version 7. Anyway you may need also the previous version (which is currently the most wide spread) to test your web pages.

Now there is a simple way to install standalone copies of Internet Explorer!

Just download the multiple IE installer at this page: http://tredosoft.com/Multiple_IE

You’ll be able to easily install old Internet Explorer versions (3, 4.01, 5.01, 5.5 and 6) and run them side by side with IE 7.

The installer currently supports only Win XP and doesn’t work under Vista.