The PNG Guide is an eBook based on Greg Roelofs' book, originally published by O'Reilly.



Other Browsers

PNG support in other browsers varies considerably by platform. On the Amiga, it is ubiquitous, thanks to a technological marvel known as datatypes (a kind of super-DLL that, among other things, provides generic image support); but under operating systems like BeOS or Atari TOS, it is virtually nonexistent. The following sections list many of the known PNG-supporting browsers, sorted by platform.

Amiga

Two datatypes provide PNG support for virtually every Amiga browser in existence: Cloanto's (http://www.aminet.org/pub/aminet/util/dtype/PNG_dt.lha) and Andreas Kleinert's (http://www.aminet.org/pub/aminet/util/dtype/akPNG-dt.lha). Cloanto made their first version of available within months of the PNG specification freeze, thereby making the Amiga the very first platform to support PNG in web browsers. Andreas's datatype at one time was considered to have better overall PNG support, but the two datatypes appear to have comparable features as of early 1999. Unfortunately, the datatype architecture itself currently precludes alpha transparency and progressive display, but an operating system upgrade due in the second quarter of 1999 is expected to add at least alpha support.

In the meantime, there are three Amiga browsers with native PNG support in addition to basic datatype support: AWeb (http://www.xs4all.nl/~yrozijn/aweb), iBrowse (http://www.hisoft.co.uk/amiga/ibrowse), and VoyagerNG (http://www.vapor.com/voyager). The first two claim to support transparency, possibly including full alpha support. AWeb also does gamma correction, and all three display PNGs progressively as they download.

Acorn

In addition to Browse, PNG is also supported on the Acorn platform by ANT Fresco (http://www.ant.co.uk/prod/inetbroch/fresco2.html/), ArcWeb (http://www.dsse.ecs.soton.ac.uk/~snb94r/arcweb), and DoggySoft's Termite (http://www.doggysoft.co.uk/trweb.html/) and Webite (http://www.doggysoft.co.uk/prog4.html#web/) browsers, although the latter two do so via a third-party helper application called Progress from David McCormack (http://www.atlantic.oaktree.co.uk/software/termite/progress.html/). Fresco is also notable as the browser chosen by Oracle for its network computer.

BeOS

As of this writing, the best bet for a PNG-capable web browser running under BeOS is a toss-up between the upcoming Opera port to BeOS, which will presumably include Opera Software's recently added PNG support, and the upcoming release of BeOS R4.5 and NetPositive 2.1 (http://www.be.com/beware/Network/NetPositive.html/). The latter is Be's bundled web browser, which in its beta version already supports PNG--though not alpha transparency or gamma correction. BeOS R4.5 will ship with a PNG ``Translator,'' which is the BeOS version of the Amiga datatype concept.

Macintosh

Surprisingly enough, given the Mac's popularity among graphic designers, there are only four PNG-supporting browsers for the platform, as of early 1999. That Netscape Navigator is one of them, and that Internet Explorer is also available (though without PNG support until version 5.0 is released) presumably has a great deal to do with this lack of other PNG support. Aside from Navigator, the only known PNG-supporting Macintosh browsers are iCab, Spyglass Mosaic, and versions 3.0A1 and later of NCSA MacMosaic, and development on both of the Mosaics ceased in 1996. iCab is a promising new browser for both Classic and Power Macintoshes; as of this writing, it is still in beta (Preview 1.3a) and has no gamma support or progressive display of interlacing, but it is reported to support alpha transparency. It is available from http://www.icab.de/.

There are also two or three plug-ins for Mac versions of Netscape prior to 4.04, depending on how one counts: the PNG Live 1.0 plug-in for PowerMacs, Sam Bushell's (beta) plug-in, and Apple's QuickTime 3.0 plug-in. Since Sam Bushell was also responsible for PNG support in QuickTime 3.0, it may be considered the successor to his own plug-in.

NeXTStep/OpenStep

Only one currently available browser for NeXTStep and OpenStep supports PNG natively: OmniWeb, versions 2.0 and later, available from http://www.omnigroup.com/Software/OmniWeb/. OmniWeb displays interlaced images progressively and does full gamma correction, but version 2.0 has no support for alpha transparency. (Version 3.0 is still in beta as of February 1999; its release notes do not mention PNG or alpha transparency.) Another NeXT browser, NetSurfer 1.1, once supported PNG, but it is no longer available.

OS/2

Until mid-1998, the options for native OS/2 PNG-supporting browsers were almost nonexistent: they included a widely distributed plug-in from Giorgio Costa and a beta plug-in from Panacea Software that was available for only two weeks. These could be used with IBM's OS/2 port of Netscape Navigator 2.02. (IBM's own WebExplorer browser never supported PNG in any way.) But September 1998 saw the public release of IBM's Navigator 4.04 port (http://www.software.ibm.com/os/warp/netscape), which includes native PNG support.




Last Update: 2010-Nov-26