SANCHO is the friendliest sidekick. He’ll never serve you a sentence longer than ten words. The sentences all have simple structures. Words with more than four syllables are replaced.

We start on SANCHO in primary school. He teaches us to read and understand texts. That is his goal—to help us understand. Most books become shorter with SANCHO.

Some people like to play a joke. They give SANCHO complicated manuals of advanced physics. It is not a very good way to learn physics.

Some people stay with SANCHO all their lives. They like how he makes reading easy. One cannot blame them. He is the friendliest sidekick.

Some of us move on to FRIDAY. FRIDAY isn’t so concerned with simplicity, but rather with finding the best way to tell a story to whoever might be reading. When you install FRIDAY, she starts learning about you. She looks at your metadata and builds a psychological profile. She maps perceived mood against weather and location and social interactions. She tracks your gaze, senses your micro-expressions, and cross-references this data with the text, so that she learns what makes you smile, what makes you gasp, what provokes emotion in you. She uses this information to predict what kind of an experience you want from the words on the page, and that’s what she serves you.

FRIDAY knows, after you’ve been reading with her for awhile, how long you want to read. She knows where you like to read. She knows the optimum volume of ambient noise for a peak reading experience. She knows that you read on the train, of course, but she also knows at which station on your morning journey, statistically, you begin reading, and at which one you typically stop, look up, and gaze out the window.

Some people are afraid of FRIDAY because her algorithms are so precise and so personal. Some people say it’s scary reading a book with FRIDAY. But the truth about FRIDAY is that she’s also friendly. She doesn’t want anything more than for you to be happy, for you to enjoy the act of reading, for you to read the perfect story, the perfect article or essay, every time.

We don’t need to talk about TRIVELIN.

Why are you bringing up TRIVELIN? He’s not useful. TRIVELIN only plays tricks on you. He lies. He omits words. Sometimes he omits . He moves text around. They say TRIVELIN was created by a hacker collective, but no one wants to take credit for it. No one wants the grief. The thing about TRIVELIN is that he’s skinned just like FRIDAY, so you don’t know he’s messing with you until it’s too late. Why are you bringing up TRIVELIN?

But here’s the thing: some people actually like TRIVELIN. They’re masochists, of course. They say he keeps them on their toes. I know of one person who reads exclusively in TRIVELIN. She’s never given me a good explanation of why. All I can think is that secretly, she thrives on chaos.

More common are the casual “Trivelinos,” people who switch back and forth between FRIDAY and TRIVELIN, to keep things interesting. Some people even install TRIVELIN within FRIDAY, so that FRIDAY herself can learn to sub-switch to TRIVELIN functionality when she senses that it’s appropriate.

And here’s another thing. Some people say that TRIVELIN is the only way to read some texts. By forcing unexpected cognitive leaps, by juxtaposing disparate themes and ideas, TRIVELIN reveals their secrets in a way that no other sidekick can, in a way that transcends even the original source material. TRIVELIN is the key that unlocks them. For a few people, it comes close to religion.

But also, TRIVELIN lies.