But both of these eateries--housed in soon-to-be-developed buildings--may serve their last meals in the next few months, as renovation costs push rents higher than the mom-and-pops of the Square can afford.

Sue E. Kuelzer, co-owner of Grendel's, said the exorbitant rents that result from development "prevent many new, unique and funky businesses from starting up."

While landlords and developers can legally choose their tenants at will, groups like the HSDF would like them to consider what has historically been the special character of Square businesses.

"You don't have much power at all," said Gifford. "It's mainly moral persuasion. It's convincing landlords that it's not best to keep run-of-the-mill stores."

It's the mix that keeps the Square vibrant, say community leaders.

"We shouldn't tilt the development in any one direction," said Duehay. The councillor said it is important for tenants and landlords to consider themselves both as independent free enterprises and members of the Square community.

For example, the Square's third Starbucks--new this year to Church Street--was what Executive Director of the Harvard Square Business Association Kristin Sudholz called a good addition because it recognized its responsibility to the city. The Starbucks offers much-needed public bathrooms to tourists and residents.

"Mallification is a common misconception," Sudholz said. Both chains and independent stores open and close at a regular rate.

"If you can make it in Harvard Square, you know you have a product that appeals to a lot of people. The opposite isn't necessarily true--as many chains have learned over the years," Sudholz said. "The Square is a unique retail experience."

--Vincent B. Chu and Jason M. Spitalnick contributed to the reporting of this story.