For online gamers whose computers run on something other than a PC (Windows) platform, it’s still slim pickins out there. I'm not aware of any casino that offers downloadable software for non-PC platforms but choices are improving for users of Macintosh and other operating systems, as more developers of gaming software are creating casino games that use Java or Flash technology. These should work well on a Mac, especially if the player uses Internet Explorer for their browser.

WebTV owners, however, are out of action when it comes to online gaming. They will have to wait until true interactive TV, which is doing well in the United Kingdom, arrives in the U.S.

Downloadable gaming software provides better graphics than Java or Flash games, said Diane Gartshore, "because you can put so much more on the user’s computer." Gartshore is director of product management for CryptoLogic, the Toronto company that’s one of the major developers of gaming software.

Experts estimate that Mac has less than 5 percent of the home computer market, which means that it doesn’t make financial sense for game developers to write downloadable software for Macs.

IQ-Ludorum, a London company that began as a developer of software for sports betting sites, offers casino games in both downloadable and Java versions. The latter can be accessed by players using Mac, or Unix or Linux. But the downloadable version, which offers higher quality graphics and audio, is only available to Windows users.

"We do not offer our downloaded version (to Mac users) simply because of the sheer economics of the situation," said Laurie Moore, product manager for IQ-Ludorum. "The cost to address that market segment would be nearly double, yet it is a much smaller installed base."

The cost to developers is not just in writing the software, but in testing it with different platforms and with different browsers. Paul Barnes, vice president for sales and marketing for Access Gaming Systems, a developer based in Dublin, said testing is especially costly for companies like his that only do business in fully regulated jurisdictions, where regulators impose detailed certification requirements.

"You’ve got Internet Explorer and Netscape, with three or four versions for each of those, that you have to support," Barnes said. "With Windows, there’s XP, NT, 95, 98, 2000, all of these platforms. If you multiply all the permutations of browser across platform, you come up with something quite horrific. We have to test all our games over all of these platforms. If you added Mac and Linux and WebTV and everything onto that, then you could employ a whole company just testing all these variations!"

Although Java is typically discussed as a no-download technology, there is a actually a quick download occurring in the background every time the user plays a Java game. Flash is a streaming software, so it comes across a bit at a time, depending on the speed of the browser and the Internet connection.

Barnes said companies are investing heavily in Flash technology. The goal of any software, he said, is to strike the right balance between getting the game up and running quickly and offering the best graphics.

In February, CryptoLogic began offering 14 of its games in instant-play Java versions. Gartshore said all of the company’s 35 or 40 games will eventually be offered in Java.

Java and Flash games are a growing part of the online gaming business, she said, because they appeal to the casual gamer. These are people, she said, who may want to play blackjack for 20 minutes, but who won’t bother -- at least not initially -- with a download.

In addition to Mac users, Gartshore said, Java and Flash games are well-suited to people who use different computers in different places and don’t want to download gaming software to them.

Alistair Assheton of VIP Casinos said the site’s Java games work well on Macs, and that it "helps enormously" that Apple now ships new Macs with Java 2.0 pre-installed. But only 1 or 2 percent of VIP Casinos’ players use a Mac, Assheton said.

WebTV, which was bought by Microsoft in 1997, is a device for surfing the Net and exchanging email. It’s not a computer, and therefore cannot download and store software. It can’t run Java, either.

GalaxiWorld Casino was originally compatible with WebTV, but a spokesman said that due to changes by Microsoft, that’s no longer the case.

IQ-Ludorum’s Moore said that interactive TV, which uses a full-blown computer, may be much more practical for online gaming. Reports indicate that it’s being used successfully in the UK for sports betting.