A Japanese developer named Mayuki Sawatari has used an AI tool called Claude Code to recreate the iconic Program Manager interface from Windows 3.1, a version of the Windows operating system released in 1992. This interface was used to organize applications into nested windows before the Start menu was introduced. Sawatari's project, called ReProgman, allows users to run this nostalgic interface on modern systems like Windows 11 and Apple Silicon Macs. While the initial version of ReProgman was created in about an hour, further adjustments were made to refine its functionality. ReProgman is designed to function as a modern application launcher, retrieving shortcuts from the Start menu on Windows or the applications present on a Mac and grouping them in a way that mimics the original Program Manager. Users can double-click to launch their usual software, rearrange icons, and create custom groups. The software is available in both x64 and ARM versions for Windows 11 and on macOS with Apple Silicon, though Mac users must enter a command in the Terminal before installation, as the software hasn't been verified by Apple. The project is an example of "vibe coding," a method where developers describe their desired outcome to an AI, which then generates the code. ReProgman is free to download, with a file size of about 12 to 16 MB depending on the version, and its code is published under the MIT license, allowing for open use and modification. However, it's important to note that ReProgman only reproduces the application launcher and does not emulate the full Windows 3.1 environment or support its older software. Windows 3.1 was a significant step in the evolution of graphical user interfaces on personal computers, offering improvements like TrueType fonts and better multimedia support. It also included popular games like Solitaire and Minesweeper, which many users associate with their early computing experiences. While ReProgman offers a nostalgic interface, those looking to run actual Windows 3.1 software would need to use emulators like DOSBox-X or online platforms like PCjs, which provide virtual environments for running older operating systems and applications directly in a web browser.