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You’ve all heard about XML. It seems to be the big buzzword being thrown about by numerous real estate technology wizards. Everywhere you turn, someone else is jumping on the XML bandwagon, claiming that XML will solve all of your data woes and ailments. Rare is the pitch for technology that doesn’t include some mention of XML. With all this talk, however, very few people attempt to address the actual business benefits that XML can provide. To that end, I wanted to take this time to try and explain: what is XML, what is it good for, how will it impact the real estate industry, and also some of the things that XML is not. XML: THE BASICS Let’s start with the basics. XML stands for eXtensible Markup Language. It is a standard approved by the World Wide Web Consortium (W3C), the same standards body that brought you other Internet standards like HTML. In fact, HTML and XML are closely related, and indeed, look very similar. However, XML is much more rigid in its definition and can address a number of problems that HTML is simply not designed to address. XML provides a method to "markup" or annotate documents (or data) in order to add meaning to the document/data. For example, the number "35" sent from one computer to another is essentially meaningless until you provide some context such as "age" or "waist size" or "annual income" to go along with it. Computers have had methods of adding meaning to documents and data for years. However, these methods were not very standardized nor were they very widespread. XML standardizes the method of adding meaning to documents, and allows both the data and the meaning to be stored within the same document. In doing this, XML still allows different people or computer applications to customize the mark up in ways that best suit the particular task at hand. Now, you might be thinking, "You say that XML provides standardization, but still allows for customization. Aren’t those two concepts mutually exclusive?" Within the answer to this question lies one of the main advantages of XML. XML, by way of a concept called a DTD, or Document Type Definition, allows a computer program to specifically define the structure and meaning of the data that appears in a particular XML document. Applications are free to use any DTD that is appropriate. There might be a DTD defined for legal briefings, another for a mortgage application, and yet another for a library. These DTDs will be entirely different, because they store information in largely unrelated areas. Yet, two or more applications that adhere to the same DTD will be able to exchange data without prior knowledge of the other application. It is in this way that XML can be both standard and customizable at the same time. XML FOR REAL ESTATE So how does this relate to real estate? There is currently a serious effort by the National Association of REALTORS® to define an XML DTD for real estate property information. Moore has been an active participant in these efforts, which is called the NAR-Sponsored Data Exchange Standard. Because different MLS systems store such widely divergent data, the definition of this DTD has been a very difficult task. As of this writing, the taskforce defining the DTD has chosen to have the DTD refer to a subset of fields that might be expected to be common between systems. It is this commonality that will allow both data exchange AND the ability for the receiving program to interpret and use the data it has received. Once the DTD has been approved as a standard, you will see many of the real estate software vendors begin to support this DTD within their products. You will begin to see a wider variety of software to process listing data, since the barrier to obtaining the data from a wide variety of MLS systems in a standard format will have been significantly lowered. You should see a wider variety of products that you’re already familiar with, such as CMA, flyer, Web, market share, mapping and forms applications. You should also begin to see new applications, many of which have not yet been envisioned. Of course, access to the data will still be subject to the locally defined business rules. Access will still require a user name and password, and the available fields will be subject to security rules. XML, being an Internet technology, will have some significant benefits around Web publishing of listing data. Most current Web browsers have some sort of support for XML, and that support is increasing very quickly. The availability of property data in XML, along with some additional Internet standards and more powerful Web browsers, will enable MLS operators and brokers and agents alike to have more control over the display of property data on Web sites. The MLS will continue to be the definitive source for local market property data, but will gain much flexibility in how that information can be presented within the Web browser environment. WHAT TO DO You may have heard some vendors say that their products support XML. The important questions to ask are "What DTD are you using?" and "In what way is this beneficial to me?" As was stated earlier, simply providing XML out-put from a computer program may not give a great deal of benefit – the usefulness of the output is only as good as the DTD definition being used and the acceptance of that DTD by other software that you wish to use. What should you do to begin preparing for the eventual arrival of XML? Begin to educate yourself on XML. Continually ask questions as you gather information and recommendations from your technical advisors, and always work toward finding out how the technology is going to benefit you and your membership. Get involved in the NAR standards effort, and support the work being done by the task force. |
