Replit is a cloud-based in-browser IDE that supports fifty-plus programming languages, offering features like real-time collaboration, GitHub integration, and detailed edit history. This guide demonstrates how to install Mastodon, an open-source social networking software, within Replit's Nix environment. To set up Mastodon, users need to configure various files, including the `.replit` and `replit.nix` files, as well as create directories for databases like Redis and Postgres, and NGINX server. After setting up these components, users can download and install Mastodon from its GitHub repository, configuring it according to their needs. With this installation, users can access their Mastodon instance through Replit's URL, enabling them to use the platform as a full-blown workspace for teams, educators, and interviewers.