The Opera Browser will soon be released to support the webkit prefix, which was designed and spec'ed to only be supported for css properties in development by webkit browsers (safari and chrome). Who is to blame? Opera points the finger squarely at webkit for not following standard procedures and at developers who aren't writing according to standards and aren't even including the prefix-free version of properties in their code. I'd be interested in seeing some real data as to how many sites are doing this and what properties they are using. It seems like a horrible practice and I've not met anyone who's fessed up to doing it on production level projects. They should be at least using the non vendor property and are most likely using some sort of starte package, boilerplate, framework or preprocessor or tool that does all the prefixing for them. So where's the data?
Opera confirms WebKit prefix usage | News | .net magazine
Open web under fire as Opera argues author errors forced its hand