Putting the squeeze on XML
The Fast Infoset plan, which represents more than a year of work, proposes that XML documents get shrunk down into a binary format in order to speed up transmission of files over the Internet. Sun has chosen a compression method that's already a standard used in the telecommunications industry.

The Sun engineers behind Fast Infoset argue that binary encoding is necessary because it can greatly improve performance, which is necessary in certain situations.

In initial tests, they found that applications perform two or three times faster when using the software. The goal of the Fast Infoset project is to generate interest among developers and eventually create a standardised binary format.

Manufacturers of consumer devices such as Canon, as well as mobile-phone companies such as Nokia, have argued for a binary XML format. Without it, large files such as images will take too long to download to devices such as cell phones, they argue.

The primary concern is interoperability. Potentially, several different binary formats for specific purposes could emerge, which are not universally understood. For example, there may be a method for encoding images sent to consumer electronics, which may differ substantially from others.

Bray is skeptical of the entire notion of converting XML to any format other than text.

"The fact that XML is ordinary plain text that you can pull into Notepad...has turned out to be a boon, in practice," he said. "Any time you depart from that straight-and-narrow path, you risk loss of interoperability. Experience with interoperability via XML as it is, has been excellent. Why take chances?"

Bray noted that there are methods for speeding up XML traffic other than creating a binary format. Advances in networking and processing power go a long way in addressing performance concerns, though perhaps not on battery-constrained mobile phones, he said.

Janet Perna, the general manager of IBM's information management group, said one alternative to binary XML is to handle the mushrooming in XML traffic with faster networking. Five or six years ago, people thought that the Internet would be too slow for doing online commerce, but the industry eventually overcame those barriers, she said.

"I don't see (growing XML traffic) as a limitation here. I think we'll keep up with it," she said.

ZapThink, a research firm specialising in XML and Web services, echoed concerns over binary XML, notably the possibility of proprietary implementations. ZapThink analysts also noted that an XML message can touch several different pieces of software and hardware, such as security systems, all of which would support any binary XML standard.

ZapThink's Ron Schmelzer said binary XML may be limited to niche uses such as high-volume applications, which demand the best performance.

Leader Technologies' Lamb supports the idea of binary XML but with one important caveat--that it be standardised.

"The amount of transactions that contain XML continues to exponentially expand, so we don't want to get caught behind the problem," he said. "But if we can't achieve a standard (binary XML), then my support would go way down."