Realtor group houses all kinds of Open Source projects


Author: JT Smith

By Daniel P. Dern

The more than 800,000 real estate professionals who constitute the membership of the
National Association of Realtors — the largest trade association in the United States — and the tens of millions of commercial and residential customers they serve probably won’t realize it, but many
will soon be benefiting from Open Source software, thanks to projects being done
by the NAR’s Center for Realtor Technology.

Intriguingly, many of the center’s projects involve Open Source software other than Linux and some,
although they contain or are code, are intended as reference standards rather
than as off-the-(virtual)-shelf software. NewsForge first reported on one of the center’s projects, a “real estate office-in-a-box” project, promoted during a Linux trade show in November.

Founded in August 2001, the center’s goals include “advocacy, implementation
and information,” according to Mark Lesswing, center v.p. “The NAR wanted
a section to hold up the technical side of real estate.”

Implementing ideas

“Advocacy” includes suggesting vendors that implement
features based on their usefulness to the NAR’s membership, rather than marketing
features easiest for vendors to implement, as well as encouraging members to make greater use of technology. “Information” includes surveying members, offering opinions on technology directions, and reviewing products from new and smaller vendors such as Sharp’s Zaurus Linux PDA and Danger Inc.’s HipTop “convergence” device.

“Implementation” is where Lesswing, along with strategic architects
Aubrey Jackson and Keith Garner, plus developer and system administrator Ian Smith and others come in, as do the Open Source initiatives.

The NAR has a mandate that agents should be able to download listings
off the Multiple Listing Service. RETS, the Real Estate Transaction Spec, defines the XML database for these transactions. However, that’s simply a standard; users need
actual implementations.

The center is not directly in the business of creating software;
that role is served by software developers, system vendors, integrators and other
parties. “We provide reference implementations of features for use by our members
and by the vendor community,” states Lesswing. “We look at new feature sets and
new business models, and provide a reference implementation — our goal is to
make these production-quality.”

For example, Lesswing explains, “When we began looking at RETS projects,
only a few vendors’ implementations conformed to the spec. This meant they couldn’t interoperate, because different vendors hadn’t implemented the spec properly or had been selective about what parts of the spec they would support. There’s no compliance testing within the RETS community.

“The center’s RETS project gives developers and vendors a reference
implementation, so they can know how to conform to the spec. It helps the vertical
industry — Realtors — if its vendors all do it correctly.”

Helping to create working software

These reference implementations are working software.
RETS is an Open Source XML project done completely in Java, for both Windows and Unix/Linux platforms.

“The standard is already defined, we’re doing code that implements it,
as a service to the vertical,” says Lesswing. “We’re using the Open Source
perspective to speed adoption of the (RETS) standard. The RETS server is in Java, and will run almost anywhere Java will run, and the client side is in PHP; we’ve tested it in Apache and IIS.”

Garner says that on top of the RETS projects, some per-Realtor or per-brokerage customization might be needed, “like branding graphics, or adding more look and feel.”

Jackson says the projects are intended to be demonstrations. “There may be things you
decide you have to change to make it work the way you want, or features you want to add.”

The Open Source angle

And that’s where Open Source comes into play. “All the code we do is available on an Open Source basis,” says Lesswing. “By making the code freely available, we believe we can help speed adoption of the standards, reduce the total cost of systems, and make it possible for systems to be created faster.”

The center’s efforts are being made available under a variety of Open Source
licenses. “The specific type of Open Source license depends on the project,”
Garner says.

Most are released under the GNU General Public License
or the GNU Lesser General Public License. One exception is the DMT Utility, an SQL parser. “It’s kind of a translator, it’s really handy, and we don’t think everyone should have to reinvent it, because it’s hard to do right,” says Garner. “So we’re going to do it under the
BSD License,
so if people want to they can just incorporate it into commercial apps.”

In addition to RETS, the center currently has several other
projects in various stages of development or deployment, most of which are
listed on their site’s
project area

  • RCCG, the
    Realtor-Client Communication Gateway,
    also listed on freshmeat. Written in Java, this Web-based system lets real estate agents and their clients talk online about real estate

  • eXML,
    an environment for exchanging information based on XML. According to Lesswing,

    “eXML is a reference implementation of socket-based communications — it does
    HTTP 1, 1.1, will stream out straight binaries, XML, etc. We use eXML to
    implement our RETS server, RETS will run as an eXML module.”

    eXML is written in Java. Its front end is written in PHP, and, according to
    Lesswing, can run on Apache or IIS — including Apache running on Windows 2000,
    98 or XP (as well as, of course, Linux).

  • VisualKeeper
    , an image management system intended primarily for large
    brokerages to centralize images or multiple listing services that manage images as a business. VisualKeeper is written in PHP.

The group has also created a variety of tools, using Open Source, to help
developers work to the RETS standard, including
DMT, written in C++, and DSNC, written in Python.

Garner, along with independent developer
Dave Dribin,
is working on a virtual mail server system that’s
about to be posted; most of the coding is done, and the two are wrapping up

“We’re using Open Source technology, including PostFix, Open LDAP,
and Courier IMAP to set up an entire email system, using the
LDAP database as the back end,” explains Dribin. “It’ll run on Red Hat or any other
Linux/Unix, and we’ll be writing a Java administrative front end, which
will also be Open Source.”

Included is a how-to document, Lesswing says. “We’ll release it
soon, and install it at a service provider to show. There are at least five
state-level realtor organizations who have expressed interest in this.”

Controlling information locally

Currently, real estate information services are highly centralized,
says Lesswing. Jackson is looking into the impact
of peer-to-peer technology such as Sun’s JXTA framework for the real estate industry.

“I’m looking at allowing people to keep their info local and operate
at the edges of the network, share info in a P2P fashion,” Jackson says.
“Realtors like to keep their info local, feel more comfortable
having control over all their information.”

“As you go to an aggregated model, the cost of support gets almost
prohibitive if members have to support it,” adds Lesswing. “An
aggregated site might have to rely on ad revenue,
which isn’t working these days.”

By contrast, notes Jackson, “you can now buy server-grade machines
for five hundred dollars.” Implementing these in a P2P fashion
“will allow people to keep control over their data, and do their
business the way they’re used to doing it.”

Smith is pursuing similar research in the area of Web services —
how initiatives like .NET, Mono, or Sun’s Web services for Java
can be of use to the real estate community.

“We want to hone that down, on paper, and put sample services up,
so vendors who want to produce for our vertical market have a place to
start,” Smith says. “This approach allows the community to rapidly gauge the impact
of the technology.”

Ultimate goal: Saving money

In addition to the seven people directly in Lesswing’s group in the
Center for Realtor Technology, the center combines the work of other Open
Source programmers at the state and local levels, he says. About 35 people are contributing.

“It’s a different use of Open Source,” Lesswing adds.
“We use it as a driver for our vertical market segment, to help our members.”

The ultimate goal of the center’s projects
“are to help realtors do their business — faster and more
efficiently — while not changing the way they do their business,”
Garner says. “For example, if you’re selling, you an find out
almost instantly find out ‘how much are other homes like mine
selling for’ or ‘what could I buy for $20,000 more.’
And as realtors adopt products like the HipTop, we can let them
be on the instant-messaging system of their choice.

“And because it’s Open Source, somebody can change it, build on
top of it, using a consultant if they need to,” Garner adds.

One immediate benefit to real estate brokers will be clearer — and in many cases,
significantly lower — prices. According to Lesswing,
the range of cost for implementations of IDX, the Internet Data eXchange,
were running anywhere from $5,000, for a Linux box with MySQL and Apache,
to a complete redo of multiple listing systems for $500,000. “We’re helping educate the [multiple listing] service providers on how much it should cost to provide things, and give them examples of good implementations.”

The center is shifting the cost from software to education, Garner says.
“The cost is somebody’s time to learn to set up and maintain the technologies —
it’s the cost of education, not software, anymore. Plus, you can use
smaller computers. There’s no need to spend, say, $70,000 from a vendor just to
get something that works. You may have to work a little harder, but
it’ll cost much less.”

Typically, he estimates, for a listing service serving 15,000 Realtors,
“if a new vendors wants to put Web services up, they’ll say to get
four to eight new machines as servers. You probably
don’t need that, but if you’re the CEO, you go along with
what the vendors say, because before our center was there,
there was no place to turn for a reality check.

“We’re making the vendors do more,” concludes Garner. “One Realtor said that we did in six weeks what they’ve been asking a vendor to do for the past three years.” contributing editor Daniel P. Dern is a
freelance technology writer. Most recently he was executive editor of
His Web site is


  • Open Source