What is Bluesky Social and how do you join?

Major changes at Twitter under CEO Elon Musk in recent months have elicited some calls for an alternative platform.

One such app, Bluesky Social, has drawn attention as a possible Twitter rival and amassed a waitlist of aspiring users.

Launched by former Twitter CEO Jack Dorsey, Bluesky features some prominent users, including model Chrissy Teigen and Rep. Alexandria Ocasio-Cortez, D-NY.

Access to Bluesky is available on an invite-only basis while the platform undergoes testing.

Neither Bluesky nor Twitter immediately responded to a request for comment from ABC News.

Here's what to know about Bluesky and how to join:

What is Bluesky Social?

Bluesky is a text-oriented social media platform on which users can post messages as long as 300 characters. Like Twitter, the messages posted on Bluesky appear on a newsfeed displayed to users. The app is available on iOS and Android.

The platform operates on an open framework, meaning that users can post their messages to a server tailored for specific interests or communities. The system design resembles that used on another text-first app, Mastodon, as well as the decentralized platform Discord.

The site began in 2019 as a venture at Twitter overseen by Dorsey, and spun out as an independent company last year.

Development of the site started after a tweet from Dorsey announcing Twitter's plans to fund a decentralized social media platform, Bluesky said in a blog post. The eventual leaders at Bluesky were among those who sent direct messages to Dorsey in response to his post, the blog added.

As of last April, Bluesky had received $13 million in funding from Twitter to "ensure freedom and independence," Bluesky said in a statement last year.

Who owns Bluesky Social?

The board of directors at Bluesky features Dorsey as well as Jeremie Miller, the founder in the late 1990s of a free instant messaging service called Jabber.

The CEO of Bluesky is Jay Graber, who formerly founded an events-oriented social media site called Happening and worked as a software engineer on a cryptocurrency Zcash, according to LinkedIn. She also serves on the board.

The company is owned by Graber as well as "the Bluesky team," the Bluesky website says.

While Bluesky has retained a traditional structure featuring a board and chief executive, the company said it aspires to take control of content away from a top-down entity and return it to creators.

"Traditional social networks are often closed platforms with a central authority," the website says. "There's a small group of people who control those companies, and they have total control over how users can use the platform and what developers can build."

The system organization offered at Bluesky "changes this," the website adds.

Dorsey criticized Musk's leadership at Twitter on Bluesky last week, saying that "all went south" at the platform after Musk's acquisition, CNBC reported.

Is Bluesky Social a viable alternative to Twitter?

Since Bluesky is still in its infancy, whether the app can compete with Twitter remains unclear.

Right now, Bluesky is much smaller than Twitter. The Bluesky app has recorded more than 360,000 downloads in the Apple store as well as over one million inquiring users on its waitlist, Fortune reported last week.

As of last week, more than 40,000 users had been given access to Bluesky, Bloomberg reported.

For context, Twitter reported 41.5 million average daily active users over the three months ending in June, which marked the last earnings report period before Musk took the company private.

The platform's user data is no longer publicly available but in November Musk said usage had reached "an all-time high."

How do you get Bluesky Social invite?

Access to Bluesky is only available to users who receive an invite, since the site is undergoing testing.

A sign-up on the company's website allows individuals to join a waitlist by sharing their email address.

The company has not offered a timeline for when it plans to make the site public.