Share My Lesson is expected to be the largest online resource for teachers in the U.S. and comes at a time when cuts to education budgets have led many districts to slash professional development.

Discussing education reform at Stanford University last year, the leader of one of the nation’s largest teacher unions decided to turn the tables and ask a question of the audience.

“You’re all technology people,” said Randi Weingarten, president of the American Federation of Teachers. “Could you actually help us?”

Weingarten said she received one call—from Louise Rogers, chief executive of TSL Education, a United Kingdom-based company that operates an online network that lets teachers around the globe access, review, and discuss lesson plans and other learning materials.

The result of that call, to be unveiled June 19, is Share My Lesson, an online portal that teachers will be able to access free of charge. It is expected to contain more than 100,000 user-generated materials.

“We’ve been trying to find a way to have teachers be able to access information quickly, actively, and share with each other,” Weingarten said. “It felt to me almost too good to be true, that some private entity had created a platform for teachers to be able to share.”

Share My Lesson is expected to be the largest online resource for teachers in the U.S. and comes at a time when cuts to education budgets have led many districts to slash professional development. AFT and TSL have pledged $10 million to develop and maintain the site, which should be ready for teachers by August.

“We must support the incredibly complex work teachers do at every opportunity, including by sharing and promoting best practices through online resources and communities of practice,” Education Secretary Arne Duncan said.

He said the program would benefit teachers everywhere.

Teacher preparation and development in the United States vary dramatically. While some schools help beginning and veteran teachers hone and perfect their craft, many other educators complain of being left to their own devices to learn the best ways to communicate and teach students with different skill levels in one class.

“For a lot of people, I think teaching is a very isolating experience,” said Karen Brennan, a research assistant at the Massachusetts Institute of Technology. “You don’t have as many opportunities as you’d like to connect with the teacher in the classroom next to you, or in the school or district. And that’s where I think network technologies have enormous potential.”

TSL Education launched its network, TES Connect, in 2008, and Rogers said it has helped create a global dialogue among teachers about best lessons and learning practices. It has nearly 2 million members from 197 countries.

“There are 79 to 80 million teachers in the world,” she said. “They are now starting to engage with each other.”

In recent years U.S. education leaders have paid increased attention to examining teaching preparation and practices in countries where students are outperforming those in the U.S. On the most recent Program for International Student Assessment, the U.S. ranked 14th in reading, 17th in science, and 25th in math out of 34 countries.

“In places that out-compete us, places like Singapore, Finland, Canada, what you hear is that their districts spend a lot more time providing them the resources and the tools to do their job,” Weingarten said. “Teachers are far more equipped when they walk into the classroom.”

There are 2.5 million lesson downloads from TES Connect a week. Most of those are matched with curriculum in the U.K., so in order to build a site for U.S. teachers, they needed to review and adapt the materials. AFT and TSL Education also wanted to make sure there were lesson plans that would help teachers implement the Common Core State Standards, a new set of academic standards that have been adopted by 46 states and the District of Columbia.

About 200 teachers from across the country helped review the lessons and prepare them for the site. Karen Gant, a science teacher in Miami, said she went to two marathon sessions in Baltimore in which teachers received spreadsheets with 100 lessons they had to review. In all, she says she reviewed more than 500 lessons—looking at language, software, and content—some of which she plans to use with her own students.

“We were surprised by the amount of information we learned,” Gant said.

One of the exercises Gant does with her elementary students each year is the classic egg drop. Students are asked to create something that will stop an egg from breaking when dropped at different heights. This year, she plans to use add a PowerPoint presentation from the Share My Lesson site that will frame the exercise in the context of a mission to another galaxy.

“It will take my kids deeper, and they’ll get involved in it a little more,” she said.