Bluesky and Nostr are both decentralized social networks, but they have different approaches and goals. Bluesky is being developed by Twitter with the goal of creating an open and decentralized standard for social media. Nostr, on the other hand, is a separate project that aims to create a decentralized social network that is more privacy-focused and community-driven.

As for why someone would work on two competing programs at the same time, it's not uncommon for developers to work on multiple projects simultaneously. It's possible that the person in question sees value in both Bluesky and Nostr and wants to contribute to both projects. Additionally, working on multiple projects can provide a broader range of experience and skills.