Firefox vs Internet Explorer
Firefox and Internet Explorer are two of the most popular web browsers in use. Firefox is developed by Mozilla Foundation and is currently at version 18.0.2. Internet Explorer is developed by Microsoft and is at version 9.
Internet Explorer is more widely used than Firefox but Internet Explorer usage is dropping rapidly.. This is due to the fact that Internet Explorer comes pre-installed on every Windows Operating System. Almost 90% of computers have IE, but it does not mean a wider use, it's because uninstalling it could cause several problems for Windows, due to its integration with the Operating System. In fact, IE has a market share of 49%, and Firefox over 32%, a value which is increasing.
 Standards Compliance and Support
Standards compliance and full standards support are two distinct concepts that are often confused with one another. Standards support implies a particular set of standards have been implemented by the browser, while standards compliance implies that any part of the standard that is implemented conforms to the specifications for that functionality in the standard.
Firefox is and has long been at least substantially, if not fully, compliant with W3C web standards. Various release versions of IE have different levels of standards compliance, with IE 7 and 8 being promoted as standards compliant updates of the browser.
Internet Explorer 8, which is currently the latest stable version, has been shown to pass the ACID test, something Firefox has not been able to accomplish. The Acid test itself is of dubious value in determining standards compliance, however, as it essentially tests for compliance with, and support for, a largely arbitrary subset of the complete standard.
While some or all of IE 7, IE 8, and Firefox may be fully standards compliant, none of them support the full modern HTML, XHTML, and CSS standards.
Both Firefox and IE (just since version 8) pass the acid2. In acid3, IE 8 only arrives to a poor 20%, and Firefox 3.5 arrives since 94%. In fact, this means problems with some styles, as working with images.
In IE 8, tabs are distribute between some processes, so, memory in theory is better used when a tab is closed (simply because the OS always manages resources better than an application), but in fact it doesn't happen. You only will feel it if you open several tabs with heavy pages and close every at the same time.
In IE, you need compilers of C#, VB.NET or C++, but there are tools to make them in "What You See Is What You Get" style, like Visual Studio, which includes the compiler. However, is harder to improve that extensions, because this kind of editors usually give a low-quality code, and very heavy addons.
Themes for firefox are written in CSS, and web editors will make them easily. You only can change the IE theme changing Windows's theme.
Due to its integration with the operating system, Internet Explorer security issues tend to become MS Windows security issues in general, causing them to become more problematic. Support for ActiveX and VBScript also contributes to security issues in IE that do not exist in Firefox.
Internet Explorer 7 on MS Windows Vista can be run in a "sandboxed" mode to reduce the negative effects of security issues on the rest of the system. Firefox, meanwhile, supports the use of a number of third-party "sandbox" tools that can provide it with similar protection.
Because of Firefox's open source development model, contrasted with the closed source commercial development model of Internet Explorer, Firefox tends to receive security updates much more quickly than IE. Microsoft has been known to let IE security issues remain unaddressed for years at a time.
The number of discovered vulnerabilities over a given period can, depending on the period you choose, appear to favor either IE or Firefox as the "less vulnerable" option. The difference in development models skew these results, however, in part because, regardless of how many vulnerabilities actually exist in a browser at any given moment:
- A popular open source application tends to receive more vulnerability reports (and even contributed security patches) from friendly developers who are willing and able to work with the application source code. Closed source applications such as IE, on the other hand, must rely almost entirely on Microsoft's staff developers to discover and patch vulnerabilities.
- Vulnerability discoveries tend to be publicly reported both more often and more quickly with open source applications, in part because of operational transparency in open source development projects and in part because vulnerabilities tend to get patched more quickly. Closed source commercial development projects, meanwhile, tend to try to downplay or even hide vulnerability reports longer -- even indefinitely in many cases -- to create an impression of security amongst users.
- Quantitative vulnerability report metrics do not usually address matters such as how long it takes for patches to be developed, severity of the vulnerability, and how likely an installation is to actually suffer the effects of the vulnerability in question.
- Because Firefox is a cross-platform application, it faces differing challenges on different platforms. This may result in one vulnerability existing on a Linux distribution, another on MacOS X, and a third existing on MS Windows, resulting in three vulnerability reports for Firefox, while only one actually affects each platform. Meanwhile, IE may suffer two vulnerabilities on MS Windows alone. The total numbers would seem to indicate that Firefox suffers more vulnerabilities, having three to IE's two, but the actual vulnerabilities that apply on a given platform would still be fewer for Firefox (only one to IE's two).
 Platform Support
Firefox runs on almost all operating systems, including Apple MacOS X, BSD Unix systems, Linux-based systems, Microsoft Windows, and Sun Solaris. Internet Explorer only runs on Microsoft Windows. Internet Explorer versions 6.5 (with no OS integration) and lower can be run on Linux systems using WINE, but this is not supported by Microsoft. In later vesions, is needed to use, moreover, IEs4Linux.
- W3Counter Global web stats, including browsers.