It's the 10-year anniversary of the beta launch of the world's most widely used email provider, Gmail. It's available today in 57 languages, and is used by roughly 500 million people.

That's a pretty incredible feat, considering Google was only about four years old when it started a team working on the mail program. From the start, the Gmail project was met with skepticism, according to the project's head, Paul Buchheit. He tells Time: "A lot of people thought it was a very bad idea, from both a product and a strategic standpoint."

Time's great Gmail retrospective, by Harry McCracken, contains a few other gems, and we dug around to find other facts about the early Google project that, a decade later, are delightful and at least a tad surprising. (They also make us feel old, but that's another story.) Happy birthday, Gmail.

Gmail's creator, Paul Buchheit, also coined the company's motto, "Don't Be Evil," in a 2000 meeting on company culture. In an interview, he said: "It just sort of occurred to me that "Don't be evil" is kind of funny. It's also a bit of a jab at a lot of the other companies, especially our competitors, who at the time, in our opinion, were kind of exploiting the users to some extent."

The proposed 1GB of storage seemed absurd a decade ago. Time reports that the "alleged storage capacity of 1GB--500 times what Microsoft's Hotmail offered--seemed downright implausible." Standard Gmail boxes are up to 15GBs each today.

Gmail was code-named Caribou. Maybe it was a Dilbert joke

Googlers raised eyebrows at the project. It was a significant effort, three years in the making. Google wasn't even talking about going public yet. The same week The New York Times first reported on Gmail's proposed soft launch into beta, Google CEO Eric Schmidt told The Wall Street Journal the company wouldn't need to move forward on an initial public offering anytime soon.

It was the work of a tiny team. When Gmail launched, there were only about a dozen Google employees working on it, according to Time.

The company called projects such as Gmail "Googlettes." Kottke pointed in 2003 to a Craigslist job posting for an "experienced, entrepreneurial manager" to give direction to project-managers of a "wide array of Googlettes." What is a Googlette? "It's a new business inside of Google that is just getting started--the startup within the startup."

It wasn't clear from the get-go that the programming language it was being built in would work for Gmail. Or anyone. From Time: "With Gmail, Buchheit worked around HTML's limitations by using highly interactive JavaScript code. That made it feel more like software than a sequence of web pages. Before long, the approach would get the moniker AJAX, which stood for Asynchronous JavaScript and XML; today, it's how all web apps are built. But when Gmail was pioneering the technique, it wasn’t clear that it was going to work."

The April 1 launch was intentional. " “Sergey was most excited about it,” Gmail's first project manager, Brian Rakowski, tells Time. “The ultimate April Fools’ joke was to launch something kind of crazy on April 1st and have it still exist on April 2nd."