Are all Web users today using Javascript-enabled browsers?

Both the Section 508 Electronic and Information Technology Accessibility Standards and the World Wide Web Consortium Web Content Accessibility Guidelines 1.0 have requirements that when content is displayed using scripting languages, the same content should be available through alternate means for those who are unable to access the scripted content. These requirements apply to client-side scripting languages, such as Javascript®, JScript®, and VBScript®.

Current and recent versions of all major web browsers have integrated support for these scripting languages. However, there are many users whose technologies do not support them. Many people still use older browsers because of the more extensive hardware requirements of newer browsers. Also, few if any web browsers for mobile devices (e.g., hand-held computers and wireless phones) fully support scripting languages, and most that do so provide only limited support. Additionally, many users still prefer the speed and efficiency of text-based browsers, as described in the Linux Journal 2005 Text Mode Browser Roundup. Of the five products profiled in the Roundup, only one (ELinks) "offers the beginnings of Javascript support". Furthermore, many users and organizations now disable scripts in their browsers in order to eliminate possible security risks associated with client-side scripts. Finally, assistive technologies such as screen readers are improving support for scripted features; even so, support varies depending on how the scripting language is being used. More information is available in the article How do scripting languages affect accessibility?.