Wikispaces, a San Francisco-based company started in 2005, enables anyone to establish a wiki. Over the years, the company realized that educators had become a key constituency. The company was acquired in 2014 for an undisclosed sum by British teacher network, TSL Education. 

BACKGROUND: In April 2013, Wikispaces debuted "Wikispaces Classroom," aiming to give teachers a clean set of tools for helping students set up wikis. It incorporates a news feed feature so that teachers and students can more easily share what they're doing. And offers support for formative assessment so that teachers can more easily see how engaged their students are in assignments and what they're doing.

Teachers can use the site for free. Wikispaces encourages institutions, such as schools, to pay for site licenses. Licenses start at $1000 per year per 100 users and scale up. As of April 2013, Wikispaces had 14 million registered users, two-thirds of whom were teachers or students.

Officially the founders took the wraps off Wikispaces Classroom at the Education Innovation Summit. But cofounders James Byers and Adam Frey have been interacting with educators for years. Fans are, well, fans: according to the company, 72% of teachers using Wikispaces say it makes them a "more" or "much more" effective teacher.