The title is a question I ask because I hear so many different views and perspectives about HTTP compression from the people I work with, colleagues and customers alike.

There appears to be no absolute statement about the compression capabilities of all current (or in-use) browsers anywhere on the Web.

My standard line is: If your customers are using modern browsers, compress all text content — HTML (dynamic and static), CSS, XML, and Javascript. If you find that a subset of your customers have challenges with compression (I suggest using a cross-browser testing tool to determine this before your customers do), write very explicit regular expressions into your Web server or compression device configuration to filter the user-agent string in a targeted, not a global, way.

For example, last week I was on a call with a customer and they disabled compression for all versions of Internet Explorer 6, as the Windows XP pre-SP2 version (which they say you could not easily identify) did not handle it well. My immediate response (in my head, not out loud) was that if you had customers using Window XP pre-SP2, those machines were likely pwned by the Russian Mob. I find it very odd that an organization would disable HTTP compression for all Internet Explorer 6 visitors for the benefit of a very small number of ancient Windows XP installations.

Feedback from readers, experts, and browser manufacturers that would allow me to compile a list of compatible browsers, and any known issues or restrictions with browsers, would go a long way to resolving this ongoing debate.

UPDATE: Aaron Peters pointed me in the direction of BrowserScope which has an extensive (exhaustive?) list of browsers and their capabilities. If you are seeking the final word, this is a good place to start, as it tests real browsers being used by real people in the real world.

Once again it is time to analyze browser usage in the US for the last month. July saw the appearance of Firefox 3.5, which has replicated the pattern seen with Internet Explorer 8, where it supplants the previous version slowly and linearly as people get around to upgrading.

Can MSIE 8 overtake MSIE 7 in August? How much will Firefox 3.5 usage grow in August and will it replace FF 3.0 as the dominant version in the Firefox family?

As with previous analyses, Internet Explorer 6 retains its iron grip on the corporate, custom Web application market. The question is not when, but if, this browser will actually fade away. It is unlikely that Internet Explorer 6 will disappear until Windows 2000 and Windows XP percentages are in serious decline.

This points to a larger concern that organizations will have to face within the next 18 months: What do they do when the Windows 2000 lifecycle terminates in July 2010 and as Windows XP sees fewer updates moving toward lifecycle retirement in 2014? [See the Microsoft LifeCycle information here]

Hiding from the inevitable just makes changes that much more dramatic and difficult.

It is not likely that the patterns in the StatCounter data will change until the summer vacation season is over in the US, and students bring their shiny new computers online at the start of the school year.

June is one of my favorite months. The sun returns (although in the Boston area there are concerned that it has been replaced by clouds and humidity), the kids get out of school (and get sent to camp), and the outdoor pool opens (and I actually swim in it).

In the US browser market, Internet Explorer 8 continues its slow replacement of Internet Explorer 6 and 7, finally overtaking MSIE 6 on June 11 [Stats courtesy of StatCounter].

The great news is that Internet Explorer 6 is slowly falling of the pace, relegated to large companies with proprietary code and a degree of inertia that impedes their movement to accepting new browsers.

The two-month trend does show some very dramatic changes, most notably with Internet Explorer 7 and Firefox 3.

While these changes appear dramatic, the lack of absolute values to base the StatCounter graphs on means that it’s very difficult to determine if these values are a result of a shift in the actual browser market, or a result in decreasing numbers of visitors to sites with the StatCounter tracking code.

Worldwide for June, the primary trend is that the decrease in Internet Explorer 7 is matched almost precisely by the increase in the use of Internet Explorer 8.

Firefox 3 and Internet Explorer 6 remained almost completely unchanged through June, indicating that the US trend is very different than that seen throughout the rest of the world. The tracking trend indicates that Firefox 3 could have overtaken Internet Explorer 7 by the end of July.

Could have is used purposely here, as the release of Firefox 3.5 will fragment the market share for this browser, and it is not likely that it will match the stats for Firefox 3 immediately.

Despite all the claims that the browser war is over, and that applications have moved beyond the browser, it is highly unlikely that this dream will be realized in the consumer browser market until late 2010, when the effect of Windows 7 can be seen on the use of Internet Explorer 8 .

Overall, June 2009 was a month of substantial shifts in the US browser market, which will be further aggravated with the release of Firefox 3.5, and the slow and steady adoption of Internet Explorer 8 by consumer and business users.

UPDATE: TechCrunch has noted the ongoing shifts to the browser share market [here].

This week marks a momentous time in the history of the Internet. In the United States, StatCounter reports that for the first three days of the work week (Monday – Friday), Internet Explorer 8 usage is equal to Internet Explorer 6 usage.

Tie this to the trend of decreasing Internet Explorer usage noted late last week and the release of Firefox 3.5 RC1 and Safari 4.0 and Opera 10 in the last few weeks, and it appears that the balance of browser usage on the Internet is becoming more fluid.

Does this mean that standards will become more relevant? Can you truly count on limiting customers to one browser?

Will browser lock-in for certain applications continue to be considered acceptable?

Since its GA release on March 19 and its addition to Windows Update in late April, Internet Explorer 8 has been gradually increasing its market share in the US. Based on the current growth pattern in StatCounter’s GlobalStats data, it appears that Internet Explorer 8 will overtake Internet Explorer 6 sometime in late May or early June.

In other parts of the world, the adoption of the new version of Internet Explorer is substantially slower, and affected by regional differences in the browser population. Europe is notable in this as MSIE8 has just overtaken Opera 9.6 in the browser population in the last week.

In Asia, Internet Explorer 8 has moved into fourth in browser share, but is a substantially lower percentage of the population than the top three browsers. In a frightening statistic, Internet Explorer 6 is the most popular browser in Asia, indicating that path to adoption may be longer in this region.

Overall the adoption of this new browser as a replacement for Internet Explorer 6 and 7 is slow and steady. MSIE8 does not appear to be significantly cutting into the Firefox population, but this could change as people begin to hear more about the features of the new browser, and Web sites begin to be designed to its features, rather than those of MSIE6 and MSIE7.

At CNet News today, the article What browser wars? The enterprise still loves IE 6 nicely sums all the reasons that Internet Explorer 6 is still in use in enterprise environments. The dominance of Internet Explorer 6 in the workplace is something I discussed a few days ago, supported by the pattern of higher weekday use of this browser during the work-week.

Limiting employees to a browser that is considered an ancient technology by Web developers poses an interesting dichotomy to companies. Internally, they are powering their internal applications with coal and steam, and turning the cogs of business with leather drive-belts. Externally, the customers get to see a site that is shiny, one that has all the gadgets of a rich-Internet application that require the computationally advanced capabilities of a modern browsers.

To some extent, the companies who use Internet Explorer 6 internally are saying to their employees that the Internet is simply another desktop application that they must use.

I am firm believer that the Web will be the home of many of the applications we use on a daily basis in the very near future [here and here]. My vision of this is that the Web application is designed to free the user, and lessen the workload for IT departments.

Most organizations continue to see the Internet as a negative, a threat to productivity, a necessary evil. So if they restrict their employees and provide them with a browser that doesn’t quite work properly on the Internet, they still have ultimate control.

I have had the benefit of working for organizations throughout my professional career that did (do) not limit my choice of browser or operating system, allowing me to find my own preference. I realize that this is rare in corporate Industrial Culture, and I consider myself lucky.

So, why is their still a need for Internet Explorer 6? Frankly, there is really no need for it in my opinion, and the CNet News article has a table from Forrester that supports that. That doesn’t mean that my browser idealism and utopian dream of “may the best browser win” will hold any sway over the IT decision makers in large organizations.

StatCounter still shows that during the week, Internet Explorer 6 holds 12% of the browser share in the US [here]. So, will this 12% of the browser world hold back the promise of the Internet for the rest of us?

Tristan Nitot and Eric Meyer comment (Tristan : Eric) on the seeming resistance by Microsoft to move MSIE towards a greater degree of W3C Standards support.

As a hack and slash Web developer, the presence of standards is a necessity for me. I can read the W3C description of the <div> tag and it’s child attributes and be able to implement it on my site.

The interesting that is not mentioned in the this is that MSIE lacks support for a number of HTTP-level standards as well. I know that most designers only worry about the screen results, but us Web performance wanks have to worry about the performance repercussions of a new browser release.

The most stunning example of this is continued resistance in some camps to the use of compression, and the utter lack of support for HTTP pipelining in MSIE.

Resistance to compression is a result of broken compression algorithms in older versions of MSIE. If you are actually still using one of these browsers, or an OS that does not support a new version of MSIE, the Web is mostly broken for you anyway, so compression is just another headache.

HTTP Pipelining is supported in all of the browsers…except MSIE. HTTP Pipelining is the ability to request multiple objects simultaneously across the same TCP connection. As most Web objects are small, the immediate impact to Web performance is astounding.

MSIE 6 is a vast improvement over the previous generations that have come out of Redmond. However, it would be interesting to have Microsoft on the side of Web performance as a major provider of server and client software.

Now, if we could only get the Mozilla.org folks to “liberate” the Netscape Enterprise/SunONE Web server code and bring that dinosaur into the modern age, we would all be a happier lot.