Five years ago, a group of Philadelphia educators dreamed up Edcamp, a grassroots training program for teachers and by teachers that has spread across the country and abroad.

On Monday, the founders and a group of Edcamp enthusiasts gathered at the University of Pennsylvania to celebrate a $2 million grant the Bill and Melinda Gates Foundation awarded to the Edcamp Foundation to further its mission of supporting good teaching.

"We're in the company of an amazing group of empowered educators who want to change the world for kids," said Kristen Swanson, acting chair of the Edcamp Foundation.

Philadelphia School Superintendent William R. Hite Jr. told the gathering, "Congratulations, Edcamp, for creating a magnificent platform and vehicle for teacher growth."

He added: "This is something that began here in Philadelphia, like a lot of things. And like all the other things, it has gone across the country and all over the world."

Edcamp holds what it calls "unconferences" - training sessions where attendees decide the topics discussed. Educators attend voluntarily and on their own time. They participate in sessions that interest them and lead those in their areas of expertise.

No vendors try to sell products or services, and the sessions are free.

More than 700 Edcamps have been held since the first was held in the city in 2010. Although a majority of the one-day events have taken place in the United States, the movement has spread to 25 countries.

Hadley Ferguson, Edcamp's executive director, said that among other things, the Gates money would be used to hold regional summits for Edcamp organizers, and to provide "discovery grants" of up to $1,000 for teachers to help them implement ideas they get from Edcamp at their schools.

"I think these discovery grants are going to be amazing for teachers, because there are so many times when you want to implement an idea, and you don't have the funds to do it," said Ann Leaness, a teacher at Philadelphia's Science Leadership Academy @ Beeber.

One of the original Edcamp founders, Leaness was surprised Monday when she was awarded one of the inaugural grants. She will use the money to change the way her classroom is set up to include activity-based zones. The room will include a writing area and a reading corner with beanbag chairs and comfy cushions.

"It's very easy to talk glowingly about Edcamp," said Matt Murray, who received a grant to help him integrate technology with the curriculum at the Philadelphia School, a private nonsectarian institution in Center City.

He said the usual professional development programs for teachers are passive - and endless.

"They talk, you take. You sit in your seat and are bored to tears for hours on end," Murray said. "Edcamp defies that model. Edcamp brings a more exciting, engaging opportunity where my voice can be heard."