The 2015 year, in many respects, was a wild one in the K-12 industry.

The school market was shaped not only by the moves of individual actors–companies winning lucrative contracts, making ambitious acquisitions, and the like–but also by shifts in state and local education policy, and by outside forces dictating policymaker behavior, such as court decisions.

States and local districts continue to sort through major political fractures over common-core testing. And districts’ buying behavior is being shaped by factors such as the long shadow cast by the Los Angeles Unified school system’s iPad woes, and by surging interest in Chromebooks, and in competency-based education.

Here’s a look back at some of the top stories of 2015–as judged by the Marketplace K-12’s most popular posts:

1. A big victory for PARCC (and for common-core testing). This summer, a New Mexico judge rejected a legal challenge to the awarding of a potentially huge (as in, estimated $1 billion) contract to Pearson by states belonging to the Partnership for Assessment of Readiness for College and Careers. If that suit, brought by the American Institutes for Research, had prevailed, there were fears that it would have sown widespread disruption in PARCC states (and in local districts). PARCC states now have more breathing room to go forward with their work.

2. Obamacare survives, again. Many districts have said that the health-care law has had big implications for their budgets, and forced them to think differently about their use of part- and full-time employees. In June, the U.S. Supreme Court rejected a challenge to the sweeping health care law, in a decision that disappointed some district leaders, most notably a group of K-12 officials Indiana, who saw the law as unconstitutional.

3. Facebook partners with a charter school network. Mark Zuckerberg’s effort to bolster the Summit Public Schools foreshadowed an even bigger announcement later: the pledge by the Facebook CEO and his wife to devote 99 percent of their company shares, valued at $45 billion to a variety of causes, including “personalized learning.”

4. Gates launches “Teacher Knows Best” website for entrepreneurs. The philanthropy’s effort offered an example of one of the vehicles arranged by nonprofits and others to try to help vendors better understand schools’ demands.

5. A Chinese company makes a big ed-tech acquisition. NetDragon Websoft LLC, a Chinese online game and mobile Internet platform company, bought U.K.-based Promethean World PLC, which sells interactive whiteboards in the United States and elsewhere. More Chinese companies are seeking routes to the U.S. market, and American and other companies are looking to invest in China, too, in some intriguing ways.

6. ETS lands a $280M testing contract in Texas, topping Pearson. This big deal came during a tumultuous year in summative testing. McGraw-Hill Education/CTB, for instance, announced it was getting out of the summative-exam game entirely, to focus on classroom-based assessment and other areas.

7. Pearson loses out on N.Y. testing contract to Questar. Questar might not be nearly as recognizable a name in the testing industry as Pearson or ETS. But the Minnesota-based company landed multimillion-dollar contracts in a bunch of states over the past year, including the New York deal.

8. Employers like competency-based education. My colleague Michele Molnar reported on employers’ craving for workers emerging from K-12 and colleges who have skills in problem-solving, teamwork, and other areas.

9. Chromebooks on the rise. K-12 systems’ interest in the portable, low-cost devices has been rising in the U.S. for some time now, driven partly by their low cost and relative simplicity. (The international picture looks much different, where Chromebooks, have only about 3 percent of the school market, by one recent estimate.)

10. L.A. demands money back for Pearson curriculum. The fallout from the nation’s second-largest district’s massive-but-problem-riddled purchase of iPads, which were supposed to be pre-loaded with Pearson curriculum, continues. Districts around the country have been watching the L.A. experience closely, and are trying to learn what went wrong, in the planning and execution.

Those were some of the biggest stories playing out in 2015. Next week, we’ll give you a preview of trends to watch in the K-12 market in the year to come.