But Crespo’s headquarters in central Havana’s trendy Vedado neighborhood is actually somebody else’s breezy front porch. The computer’s only connection to the Internet is a creaky dial-up link, and Crespo is careful to say he’s not operating as a broker, since the job is still technically illegal.

A baffling, sometimes bizarre real estate market has emerged in the year and a half since President Raul Castro legalized private home sales on this Communist-run island for the first time in five decades.

While trade in homes is now legal, the people who bring buyers together with sellers are not. The government has yet to make good on promises to legitimize brokers, most of whom still operate in the shadows.

It’s a story that has been typical of Castro’s economic reforms, which often have left little space for the sort of middlemen and other services that help markets work.

The Cuban leader also has legalized a used car market, but not the right to open a business that sells them. And while reforms have sparked an explosion of private restaurants and cafes across Cuba, the government has yet to give them access to wholesalers that could keep them better supplied.

Crespo gets around the broker ban by operating as a licensed computer programmer and photographer, helping clients list their properties on Web portals, producing the for-sale posters that hang in his office and offering digital photo services for sellers. He says he doesn’t charge commissions.

Crespo’s listed fees are just a few dollars, but he’s found himself in major demand. He estimates 30 to 40 customers a day wander into his porch-side business, called EspacioCuba. He says his service has 2,500 current listings and has helped sell about 250 properties since it opened in January.

“Right now we are very pleased,” said Crespo, a smartly dressed 28-year-old computer scientist with close-cropped hair, but he added that the market would benefit by the government made brokering legal.

The market also still lacks a workable mortgage system, an easy means of advertising potential sales and, most important, a middle class with resources to buy.

Yet sales are humming, with some 45,000 homes changing hands in the first eight months after Castro legalized the real estate market in November 2011, according to the most recent statistics from the government.