For years, computer game companies and computer stores tried to sell more games by adding a little bit of "educational" content and then claiming that it was really educational software made fun. More often than not, they were just lying through their teeth. But sometimes, they did it right. Every now and then, a company would make good on this "edutainment" market.
Take, for example, the company Broderbund. Founded in 1980 by brothers Doug and Gary Carlston, they often tried to be the clean, pure company in comparison to the wild and crazy competitors such as Sierra. But competition in that time was friendlier -- at the same time each one would try to outsell the other, they also went on vacations together, rafting trips, and the like. And there was an unspoken gentleman's agreement to not step on each other's toes so much.
So Broderbund later diverted their attentions more to educational titles, while Sierra pumped up their games. They both still did a little of each; Sierra taught us a lot about sea life, for example, and Broderbund polarized the adventure gaming community with the non-standard interface and design of their best -selling adventure.