This magazine is dedicated to discussions on the federated social networking ecosystem, which includes decentralized and open-source social media platforms. Whether you are a user, developer, or simply interested in the concept of decentralized social media, this is the place for you. Here you can share your knowledge, ask questions, and engage in discussions on topics such as the benefits and challenges of decentralized social media, new and existing federated platforms, and more. From the latest developments and trends to ethical considerations and the future of federated social media, this category covers a wide range of topics related to the Fediverse.
From what I understand, Kbin and Lemmy are two different projects.
They both use the same protocol (ActivityPub), so they can talk to each other.
The main difference is that Kbin also has what's called "Microblogging", which is what you know from Twitter for example.
They are essentially different software for, more or less, the same purpose: content aggregation with similar features to Reddit. Kbin also has microblogging features (Lemmy doesn't). They both use the same protocol ActivityPub so they can see and talk to each other.