HTML and CSS Reference
Internet Explorer reads the txt file, interprets the
code in the page, and renders as if it were an html file.
Firefox recognizes the file type and renders the
text rather than interpret the code as html.
F IGURE 1-2 Irregularities with browsers handling MIME types and file extensions
HTML and XHTML: Version History
Since its initial introduction in late 1991, HTML (and later its XML-based cousin, XHTML)
has undergone many changes. Interestingly, the first versions of HTML used to build the
earliest Web pages lacked a rigorous definition. Fortunately, by 1993 the Internet Engineering
Task Force (IETF) began to standardize the language and later, in 1995, released the first real
HTML standard in the form of HTML 2.0. You will likely encounter more than just the latest
style of markup for many years to come, so Table 1-1 presents a brief summary of the version
history of HTML and XHTML.