Safari

Built on the Webkit renderer, Apple’s native web browser has shipped with OSX since version 10.3 Panther and is the default browser for its iOS platform. Has been available to Windows users since 2007.

Safari overview

Global Market share: 14.% (September 2012; now includes Safari for iOS)
Font formats: Safari supports TrueType fonts (.ttf) as well as OpenType fonts with TrueType (.ttf) or PostScript (.otf) outlines.
Notes: Font Variant property is apparently not supported. Safari will NOT register a new font and may overwrite any font previously registered with the same name.

Safari does not seem to accept comma-separated values for font-weight!

Latest version: Safari 6

Release: Safari 6 available since July 2012
OS: Mac OSX 10.8+. There hasn't been an official statement on future support for Windows, but as of October 2012 Safari 6 isn't available.
Global Market share: 3.2%

 

Safari 5

Release: Safari 5 available since June 2010
OS: Windows XP, Vista and 7; Mac OSX 10.6.8-7.
Global Market share: 7.23%

Safari 4

Release: June 2008
OS:Mac OSX 10.4
Global Market Share: >1%
Notes: Approximately 3% of Mac users are still using OSX 10.4 (Tiger) (Source: StatOwl)

Stats via W3Counter