It looks like the Fediverse is opening up further. In late March, Meta's Threads introduced a beta feature that allows users from the US, Canada, or Japan to cross-post from Mastodon and presumably other federated social networks and view likes. In June, this ability was added in over 100 countries.
If you want to take the longer route, you can also do so via the mobile app or the web version:
Once you Fediverse Shareyou'll probably be taken through a series of explanatory screens explaining what the Fediverse is and how sharing works (you'll need a public profile), and warning you that once your post is published on the Fediverse, Threads has no control over the rules of the servers it ends up on. If you stop sharing, Meta may request that any previously shared posts from another server be removed, but that's all. [Note: these were the warnings I observed when I first went through the process in March; since they only appear the first time you enable sharing, it’s possible they may have changed since then.]
Other things to consider:
So what does all this mean?
According to Meta, this means that “your Threads profile can be followed by people using other servers on the Fediverse, and you will eventually be able to follow them from Threads.” If you have sharing enabled and select “Fediverse Sharing,” you will be reminded of your username and informed that you can now connect and share content with others on the Fediverse.
How significant this is will depend on how well cross-posting works in the future, how smooth the process becomes, and what security measures are put in place to prevent malicious actors from using it to break into servers that are supposed to be secure spaces and other issues. As mentioned above, I've been using it since March and have found the process to work well. This could be the start of a much more inclusive way of social networking.
Updated September 13, 2024: Updated to include the single link to the Fediverse sharing dialog, among other changes.