Netscape 4.x is the single biggest obstacle to standards-based web design. Graceful degradation is one thing but crashing on legal, standards-compliant HTML and CSS is quite another. This part of the MacEdition site documents all the reasons why Netscape 4.x has got to go.
padding plus some
combinations of blockquotes and hr in a table will crash
4.73 and below.DIVs with border styles crash Netscape
versions 4.0 below 4.08 if they contain
certain other tags, especially those newly introduced in HTML
4.0.float, clear and margin CSS
styles or the float, clear and
width styles. Any two of these is fine, but all three in
combination will
consistently crash this browser.margin-bottom, etc) in combination with certain other
tags. It has since been fixed in the Netscape 4 codebase, so that newer
versions of Netscape 4 do not suffer from the bug. BLOCKQUOTE element and another table will crash
Netscape 4.x if the table cells have a margin style applied, eg
margin-left:5px;. (Tilman’s page states that this
crashes Netscape 4.7x, but I have verified the issue for versions 4.04,
4.05, 4.08 and 4.6.) Tilman has also identified at least one other
page generating a crash bug in Netscape 4.7x, but the exact cause has
not been verified, and may involve non-valid code.