The developers at Alpaca have made several significant improvements to their platform and API in the past week, including the addition of support for Market-on-Close (MOC) and Limit-on-Close (LOC) orders, which can be used to target market close prices. They have also addressed issues with OPG (At-the-Open) orders in paper trading and enabled Cross-Origin Resource Sharing (CORS) for their Trading API, allowing developers to call the API from JavaScript code running on any website. Additionally, they have completed a migration to websockets for real-time data streaming, improved error messages for insufficient positions, updated mobile apps to support the new API v2, and made several security fixes, including setting an X-Frame-Options header to prevent clickjacking and dropping unnecessary authentication methods from their Trading API endpoints. These improvements are the result of collaboration between the development team and the user community, and demonstrate Alpaca's commitment to delivering a high-quality developer experience.