[webkit-dev] Removing support for the -khtml- (and -apple-?) vendor prefixes

Peter Beverloo peter at lvp-media.com
Thu Jul 8 23:39:12 PDT 2010

Good day,

While going through WebCore for some CSS research I'm currently doing,
I came across a piece of code[1] which translates all "-khtml-" and
"-apple-" vendor-prefixes to "-webkit-". This effectively means
"-apple-transform" and "-khtml-transform" can both be used instead of
"-webkit-transform". I am unaware of the rationales behind the apple
vendor-prefix, but I'd like to propose removing support for the

My main argument for this is that WebKit and KHTML are, in my opinion,
two separate engines by two separate vendors. The port occurred eight
years ago, and code in both projects has changed significantly ever
since. When Microsoft announced support for "-webkit-text-size-adjust"
in IE Mobile it was argued that browsers should not implement
properties with prefixes "belonging" to other vendors, which seems to
be exactly what WebKit is doing with the KHTML prefix.

I understand the history of supporting -khtml-, and I've heard from
the KHTML project that they implement the -webkit- prefix as well.
However, considering that WebKit has grown significantly in the past
few years and that all code changes basically made KHTML and WebKit
two individual rendering engines with individual CSS support, I
believe it would be appropriate for support to be dropped.

Peter Beverloo

[1] http://trac.webkit.org/browser/trunk/WebCore/css/CSSParser.cpp#L5583
[2] http://blogs.msdn.com/b/iemobile/archive/2010/05/10/javascript-and-css-changes-in-ie-mobile-for-windows-phone-7.aspx

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