In This Issue...

• Introduction
• Recognizing Web 2.0
• PNG Colors in Internet Explorer
• New Technical Articles
• Techy Forum Threads
• More Techy Blog Entries

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Introduction

We're hitting the home stretch for the year here at SitePoint, and everyone is hard at work on something.

Whether it's the final edits on our Ruby on Rails and Design for Developers books launching first thing in the new year, a hush-hush project to upgrade the SitePoint Forums, or my own work locked away in a quiet room recording SitePoint's next series of video tutorials, everyone has their hands full.

Still, I had enough time to prepare a talk for a meeting of the Victorian Association for Library Automation (VALA) last night called "Recognizing Web 2.0". In preparing this talk, I had the challenge of explaining Web 2.0—a concept that's hard to pin down in a room full of web developers—to a non-technical audience. I'd like to take this issue to discuss what I came up with.

Usability Kit a Surprise Hit

Meanwhile, we launched The Usability Kit quietly last week with humble expectations, knowing that, although the product was a real winner, usability itself wasn't exactly a hot topic.

Boy, were we wrong! Whether because the free sample PDF is a riveting read, or because the Magnetic Web Widgets we include with the kit are just too cool for words, sales of the kit have been surprisingly strong!

As a result of this strong showing, we're putting some serious effort into adding usability to our lineup here at SitePoint. To start with, we plan to launch a usability blog in the next week or so. Watch for it!

Speaking of the Magnetic Web Widgets, they've been really popular here at SitePoint HQ. And because we only received a few sets here at the office, they've been hard to come by—especially the very attractive SitePoint logo magnet!

Recognizing Web 2.0

In the week between being asked to speak on the subject of Web 2.0 and delivering the talk, I spent a lot of time turning over in my head the loose collection of concepts that have come to form the foundation for Web 2.0.

I've covered what Web 2.0 is about in a previous issue of this newsletter; however, presenting this talk to a largely non-technical audience meant taking a fresh look at these ideas. As I assembled my slides, here's what I came up with:

• sites as applications

  The progress of browser technology has enabled developers to produce richer user experiences that, in some cases, enable web sites to take the place of desktop applications, with the benefit that your data is stored online and is accessible anywhere you can get Internet access.

• user participation and the wisdom of crowds

  The Long Tail would suggest that web businesses should be targeting as wide a market as possible, but there are limits to the in-house expertise of any one company. Consequently, we are seeing a trend of successful web applications that generate some or all of their content as a by-product of user participation.

  In some cases, sites even release control of their navigation structures, allowing users to generate a Folksonomy through content tagging. The best and most successful examples of these extract from the "selfish" activities of individual users some valuable result for all users, thus overcoming the so-called "1% rule."

• open data and services

  It has become accepted practice for any site that expects users to input valuable information to provide some convenient and automated means to extract that information from the site in a standard format for use in other contexts. Feeds, Microformats, and APIs are all examples of this trend.

That's all fine as far as it goes, but I still felt like there must be something more, some unifying principle that ties together these disparate concepts, a central idea that is important enough to justify the name "Web 2.0." It finally came to me on the evening of the talk, as I sat awaiting the arrival of the organizer of the event.

Throughout history, each new medium (books, radio, cinema, television) has first been used to produce content equivalent to that found in existing media. The classic example is radio, which was first used to broadcast radio plays—content based on the familiar medium of theater. Eventually, however, out of the unique strengths of a medium will arise a new kind of content: one that doesn't mimic what came before, but instead delivers an experience that would never have been possible before. Web 2.0 is that stage in the evolution of the Web as a medium.

I had just enough time to whip out my laptop and add a couple of extra points to my slides before it was time to begin, and as eyes lit up in the audience I knew I'd hit on something.

If you'd like to check out the presentation in its entirety, you can grab the audio and PowerPoint slides here:

Recognizing Web 2.0 Audio (MP3, 58 minutes, 27MB)
Recognizing Web 2.0 Slides (PPT, 9MB)

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PNG Colors in Internet Explorer

With all the work Microsoft put into improving support for PNG image files in Internet Explorer 7, many developers will be taking a second look at this image file format for use on their web sites. Sadly, getting PNG images to display "just right" in Internet Explorer often requires a little hacking—but this time it's not Microsoft's fault.

I've spent more than a few evenings lately working to bring a web site I inherited up to the current state of the art in web standards. In the process, I decided it would be nice to update some of the images from GIF format to 8-bit PNG. With Internet Explorer 7 now claiming full support for PNG images, it seemed like a good time to finally leave the archaic GIF format behind.

Sadly, things didn't go as smoothly as expected. Though everything looked good in Firefox, Opera, and Safari, when I fired up the site in IE 7 I could immediately see there was something wrong: the background colors of my PNG images did not match the background color of the site.

Transparency isn't the only advanced feature that PNG boasts over GIF. PNG images can also contain a gamma correction value, which is meant to represent the relative brightness of the display on which the image was created. In theory, the browser can use this value to display the image at the exact same brightness on another display.

That's all well and good, except that other image formats and solid colours specified with CSS do not contain this gamma correction value, so when you adjust the display of a PNG based on its gamma information, it no longer matches the other colors on the site.

For this reason, most browsers (including current versions of Firefox, Safari, and Opera) ignore the gamma correction value in PNG images when displaying them on the Web. But Internet Explorer does not, and that's why my PNG images stood out in that browser.

The solution to this problem is to produce PNG images with no gamma correction information in them, so that Internet Explorer will not attempt to correct their display. Unfortunately, Photoshop's "Save for Web" feature doesn't give you that option, so you need to use a separate tool to strip out the gamma correction information that it writes.

A great tool for doing this in Windows is TweakPNG. It's open source and a free download. Simply drag a PNG to the program window and delete the "gAMA" chunk from the list before saving the file. While you're at it, you might as well delete the "tEXt" chunk as well, to save a few extra bytes of file size by removing Adobe's stamp on the file.

For the Mac, I haven't been able to find a tool quite this friendly, but if you install ImageMagick on your system you can reset the gamma information on a file using the convert command at the Terminal prompt:

convert +gamma 0 badcolor.png goodcolor.png

Once you've stripped (or reset) the gamma information in a PNG file, all current browsers should display the file without adjusting its brightness, so that it will match the other colors on the page. The only problem browser at this point is Safari 1.x, which arbitrarily corrects PNG images even when they contain no gamma information. Safari 2.0 fixed this issue, but sadly at this point it seems that users of older versions of Safari must accept the annoying color shift.

For the full story of the shamozzle that is PNG color on the web, check out The Sad Story of PNG Gamma "Correction" by Henri Sivonen.

That's all for another Tech Times -- hope you enjoyed it! I'll be back in two weeks with the next issue.

Kevin Yank
techtimes@sitepoint.com
Editor, The SitePoint Tech Times

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