Top 1000 Application Servers Survey Methodology
From May 2005 on, Port80 Software conducts periodic surveys of Fortune 1000's main corporate Web sites to discover what type of application server software or scripting platform that they are running.
This survey is conducted between the first and fifteenth of a selected month and queries a list of 1000 leading global corporations' main corporate Web sites (e.g. www.corporation.com). Port80 Software queries this list of sites via a standard HTTP 1.1 GET request, and the HTTP headers returned with the response are persisted. The HTTP header data from each response is then compared against well-known HTTP header signatures for popular commercial and open source application servers to determine the identity of the application server used on the company's main Web domain. Given the nature of application server technologies, a small percentage of companies reported in this survey may have the application server software installed on their Web server (and reported as such in this survey) but may not actually use the application server fully throughout their main corporate Web site. Since some servers are configured with more than one backend application server or scripting technology (for instance, classic ASP and ASP.NET), the percentages in the survey do not add up to 100%. However, this survey does discount for duplication within categories. For example, a site running ASP, ASP.NET and WebLogic would be counted in both the Microsoft (ASP, ASP.NET) and Java (WebLogic) Platforms categories, but the site would not be counted twice for the Microsoft Platform, even though it is running ASP and ASP.NET. This method of categorization attempts to give credit for all technologies deployed on a particular Web server while not "overcounting" multiple instances of the same technology family.
By design, this method of categorization does not attempt to account for the possibility that the HTTP header data, in particular cases, might have been altered to misrepresent the identity of the application server or scripting technology (for example by means of a product such as ServerMask).
Real-time queries of the survey list or of any Web site using Port80 Software's "header check" tool may provide different results on application server type from those published by Port80 Software.