1. Open up your Applications folder and find your old version of Firefox.
2. Right click -> Get Info.
3. Rename to “Firefox36.app”.
4. Download Firefox 4.0 and install as normal.

Voilà! You now have more than one Firefox browser to play with.

That was really simple huh? If someone knows how to do this on the Windows and Linux side, I would love to hear how.

/usr/sbin/apachectl: line 82: ulimit: open files: cannot modify limit: Invalid argument

After a little investigating it turned out to be caused by an update in the apachectl script to OSX 10.6.5.

The ULIMIT_MAX_FILES variable increases the maximum number of file descriptors allowed per child process. This is critical for configurations that use many file descriptors, such as mass vhosting, or a multithreaded server.

A quick edit of the the apachectl script and it’ll be back working.

I use TextMate, so the command is:

sudo mate /usr/sbin/apachectl

You’ll be prompted for your password.

Once the apachectl file is open, look for the following line (for me it was line 64):

ULIMIT_MAX_FILES="ulimit -S -n `ulimit -H -n`"

and replace with the following:

ULIMIT_MAX_FILES="ulimit -S -n"

This will set the correct command that increases the maximum number of file descriptors allowed per child process.

Up until very recently, the void between the Web and the desktop seemed like a schism that could not be crossed. But since AIR‘s 1.0 release in February this year, a whole host of other applications are emerging to compete with AIR in the single site browser space.

Although AIR is very new, the product is remarkably mature with the integration of the excellent opensource WebKit browser engine for rendering HTML and JavaScript, the SQLite database engine for embedded database functionality and of course, Adobe’s Flash player for development of Flash-based Rich Internet Applications. Because of this flexibility, the learning curve faced by developers is almost non-existent, they simply have to get to grips with the AIR API.

What is all the fuss about?

Delving into the AIR API, your application will have the ability to detect whether it is currently the active window or connected to the network. You can access the file system, allowing you to read and write files, access other datasources, tap into the native menu options or interact with almost any aspect of the operating system in a way familiar to common desktop applications. This functionality is available regardless of the architecture on which it is installed. Therefore AIR applications will work similarly when installed on a Windows PC or Mac, and soon on Linux machines as well.

AIR is much, much more than a single-site browser — it’s a cross-platform runtime environment and the distinction is significant.

The ability to run applications built on AIR on almost any machine, on- and offline, sets it apart from any other offering currently out there or in development. For example, Google Gears is restricted to AJAX applications, whilst Mozilla Prism isn’t much more advanced than a cut-down version of Firefox, with no offline capabilities yet.

Who else has entered the race?

As mentioned, a significant entry is Mozilla’s Prism, however, Pyro for Linux and Bubbles and Fluid for Mac are clever little tools for packaging up an existing website and presenting it as a standalone desktop application.

Mozilla Prism

Prism, previously known as WebRunner is a product in development which integrates web applications with the desktop, allowing web applications to be launched from the desktop and configured independently of the default web browser. It is commonly used with Google AJAX Applications, such as Gmail and Google Docs.

Prism is part of an experiment by Mozilla designed to “bridge the divide in the user experience between web applications and desktop applications”. Essentially, Prism will allow you to create a desktop-like application out of individual websites. These site-specific applications are a growing trend and a trend heavily marketed by, not only Adobe, but now Mozilla, as ‘the future’.

While traditionally users have interacted mostly with desktop applications, more and more of them are using Web applications. But the latter often fit awkwardly into the document-centric interface of Web browsers.

In its current form, Prism doesn’t have the ability to function as a desktop application without access to the Internet, but Mozilla says it is “working to increase the capabilities of those apps by adding functionality to the Web itself, such as providing support for offline data storage and access to 3D graphics hardware.”

More details can be found on the Mozilla Prism website.

Pyro Desktop

Pyro Desktop is a new type of desktop environment for Linux built on Mozilla Firefox. Its goal is to enable true integration between the Web and modern desktop computing. Pyro was announced during GUADEC 2007 and is developed by Alex Graveley and Chris Toshok.

More details can be found on the Pyro Desktop website.

3D3R Bubbles

Bubbles is a desktop application that allows you to work with your web resources in the way you want to work with them.

The Bubbles application window, known simply as a Bubble carries the web resource almost like a web browser does. Since the Bubble has advanced browser capabilities there’s an advanced control device for it — the Bubble seed — an XML file called Smart Bubble. It defines the properties — the whats & the hows — of its Bubble window. The Smart Bubble contains the information about what Bubble will load, how it will look on the desktop and what capabilities it will have, etc. So it goes from the Smart Bubble into a grown Bubble that lives on your desktop, accessible from the system tray.

More details can be found on the 3D3R Bubbles website.

Fluid App

Fluid is a way to create Site-Specific Browsers SSBs to run each of your favorite WebApps as a separate desktop application. Fluid gives any WebApp a home on your Mac OS X desktop complete with Dock icon, standard menu bar, logical separation from your other web browsing activity, and many other goodies.

Fluid includes optional Tabbed Browsing, built-in Userscripting (aka Greasemonkey/GreaseKit), RSS/Atom Feed detection, a JavaScript API for setting dock badges, showing Growl notifications and adding Dock Menu Items, optional bookmarks, optional browsing to urls outside the SSB “home” domain, Dock badges and Dock menus for Gmail, Google Reader, Facebook, Flickr, and Yahoo! Mail, auto-software updates via the Sparkle Update framework, and custom SSB icons.

More details can be found on the Fluid App website.

So what is the big deal? The Adobe marketing team state that:

The Adobe AIR runtime lets developers use proven web technologies to build rich Internet applications that deploy to the desktop and run across operating systems. Adobe AIR offers an exciting new way to engage customers with innovative, branded desktop applications, without requiring changes to existing technology, people, or processes.

What AIR applications should you check out?

What is intriguing is that all the tools I have chosen are generally useful tools for the developer or designer, with the exception of twhirl, which is a social-interaction tool. I’m looking forward to when other, less developer-centric tools become freely available. AgileAgenda has taken the lead with this respect, albeit not freely available, as has eBay desktop, but I would like to see examples from the BBC in the form of a desktop BBC iPlayer or maybe a Flickr image browser, del.icio.us bookmark reader, RSS aggregator and a Picnik image editor.

Analytics Reporting Suite

The Analytics Reporting Suite, by Nicolas Lierman, brings Google Analytics to the desktop. It uses it’s own custom API to interact with Google and nearly implements all the features of Analytics.

For website owners this is a must-have application. Like the twhirl AIR application below, it is a fantastic example of what can be achieved with Flex and AIR. Measuring visitor trends and traffic are essential tasks to managing and improving a websites performance. The Analytics Reporting Suite allows you to configure multiple Google’s Analytics accounts and access the web-based suite’s plethora of features via a desktop application. The application displays integrated graphs and animations via a tabbed interface, which allows you switch between a number of reports. These reports can then be saved as a PDF, Excel or XMLdocument, or printed.

You can download and install the application from the About Nico website.

twhirl twitter Client

twhirl, by Marco Kaiser, is probably the most popular desktop client for the twitter micro-blogging service. Most of the features available on the twitter website are accessible through twhirl, plus, a lot of usability enhancements have been added to make it easier to manage multiple accounts. This is great for those who want to separate business and personal accounts they may have.

The twhirl application is a great example of how AIR can bring web applications to the desktop; it can dock to the system tray, display message alerts and you can configure the applications opacity when not focused (great if you like Mac and Vista-styled themes). The application allows you to search twitter users, view their timelines, add friends, view followers, delete tweets and much much more. Twhirl automatically fetches your friends’ status updates, direct messages and replies, whilst also colour coding different types of messages and alerting you to messages both audibly and visually.

The twhirl application is skinnable and comes with several built in skins with which you can customise the application. All-in-all twhirl is not only one of the best twitter clients, but AIR applications.

You can download and install the application from the twhirl website.

Kuler Desktop

Adobe kuler is the first web-hosted application from Adobe Labs designed both to stand alone and to complement Adobe Creative Suite software. Built using Adobe Flash and ActionScript 3.0, kuler is all about colour: colour for exploration, inspiration, experimentation and sharing. Kuler is clearly targeted at the designer, but anyone interested in colour will benefit from its use.

You can download and install the application from the Adobe Labs website.

WebKut

WebKut is a web screenshot tool that allows you to capture web pages, or parts of them in a very simple way. It provides you with 3 capture options: the entire page, the current view, or only a selection. This little application proves particularly handy for those presentations or projects that need great visuals from the web.

You can download and install the application from the WebKut website.

RichFLV

RichFLV, by Benjamin Dobler, lets you edit FLV files. The key features include reading FLV metadata, read and edit cuepoints, cut FLV files, convert the sound from an FLV to MP3 format, convert an FLV to an SWF … and much more.

You can download and install the application from the Adobe AIR Marketplace website.

SearchCoders Dashboard

This Flex-based chat widget is designed with programmers in mind. The code input feature allows developers to chat about code without disrupting the conversation.

You can download and install the application from the SearchCoders website.

Pownce

Much like twhirl in look, feel and ease-of-use, but with a slant towards productivity rather than micro-blogging, Pownce is a way to keep in touch and share things with your friends or colleagues. You can send people files, links, events, and messages and then have real conversations with the recipients. This is a great collaboration tool and was one of the first services to really embrace AIR as an application architecture, which could realise their service as a desktop client. Everything that is available via the Pownce website is also available via the client application, except and possibly importantly, the ability for the user to amend their account settings and add friends to your network; this still has to be done via the website.

For a small annual amount, Pownce offers a paid-for service which will eliminate adverts from your profile and allow you to send huge file sizes (100MB) and customise the theme of your Pownce.

Pownce also offers Drupal integration and a mobile application, which works with the iPhone, BlackBerries and many more ‘internet-ready’ mobile devices.

You can download and install the application from the Pownce website.

So what is Silverlight and XAML proposition? How does it vary from Flash?

Microsoft Silverlight is a proprietary runtime for browser-based Rich Internet Applications, providing a subset of the animation, vector graphics, and video playback capabilities of Windows Presentation Foundation. The runtime is available for Microsoft Windows and Mac OS X, with Linux support under development via the third-party Moonlight runtime.

Not much difference to Flash so far…

Extensible Application Markup Language (XAML) is a declarative XML-based language used to initialize structured values and objects. XAML is used extensively in the .NET Framework 3.0 technologies, particularly in Windows Presentation Foundation (WPF), where it is used as a user interface markup language to define UI elements, data binding, eventing, and other features, and in Windows Workflow Foundation (WWF), in which workflows themselves can be defined using XAML.

Not much difference to Adobes’s MXML…

Browser support…

A frequently asked question is which browsers and operating systems will it run on? If XAML is limited in this area, its usefulness in the web world will also be significantly limited. Previous encarnations of XAML, were limited and justifiably criticised as it would only work with an ActiveX control. However, this has now been resolved with support for Firefox, Opera, Safari and Netscape, Windows and OSX alike. Support is provided by a downloadable plugin, much like Flash!

Like Flash…

Silverlight enables web developers to create visually rich user interfaces and animations, play video clips and stream media within the web page, again, much like Flash! But it is different! The comparison doesn’t end there. Animations are organised using timelines and frames within the tool…how else would you organise an animation without timelines?!

Like Flex…but not!

Where things differ from Flash are the tools used to develop the Silverlight applications. Silverlight is supposed to be a way of designing and building rich user interfaces. However, standard HTML elements are missing. The way you design a particular interface is to build a standard HTML form in your favourite editor, e.g. Dreamweaver CS3, and then open this page in Silverlight to add the visual enhancements that your design requires. This sounds complicated to say the least. In comparison, Flash has a brilliant tool and framework called Flex that does this far more gracefully and with the development of Thermo, designers can really feel comfortable in the web application development mix.

Silverlight applications will also run on mobile devices, but the plan is for the applications to only run within a mobile web browser. This is unlike Adobe who are feaverishly developing the AIR runtime to allow Flash applications to run independently of the browser environment and offline.

So, Web 2.0 and beyond with Silverlight and XAML may be somewhat jumping the gun. You may say that there is nothing new or innovative with the Silverlight offering. It does, however, serve to emphasise how important the Rich Internet arena is becoming or indeed has become.

The secret behind this implementation is a filter introduced in IE55 that is called AlphaImageLoader. This filter takes an image with alpha channels and displays it. It has also a property for deciding how to scale the image.

To download this permanently: iepngfix.zip (15kb).

How to Implement

1. Put the iepngfix.htc file into your CSS directory
2. Put the blank.gif file into your CSS directory (otherwise you will need to edit the HTC file)
3. Edit your CSS to include the following line behavior:url(iepngfix.htc); for the <img> tag

Known Issues

This uses CSS “behaviors”, a custom Microsoft extension to CSS. As such, it will not affect any other browsers like Mozilla and Opera which already implement good PNG support. It will also not help IE4.0 and IE5.0, which don’t include the necessary IE filter, and does nothing with IE5/Mac (which natively supports translucent PNG foreground images, however).

You should not apply other visual filters to the iamge with the PNG behavior because these other filters do not respect the alpha channels and the result will most likely not be satisfactory.

Alternatives

An alternative source that I recently discovered is found at the following link http://webfx.eae.net/dhtml/pngbehavior/pngbehavior.html