Check out this collection of FireMonkey styles that recreate the look and behavior of classic desktop operating systems inside modern Delphi applications which run on Windows, macOS, and Linux (plus Android and iOS).
The project takes inspiration from web projects such as classic-stylesheets and system.css, which reproduce historical desktop interfaces with CSS, and translates that idea into native FireMonkey .style files. Instead of styling HTML, the themes directly repaint standard FMX controls and can be loaded through a TStyleBook or switched dynamically at runtime. Additionally, the latest version of FireMonkey applications can be rendered with Skia (the graphics library that powers Google Chrome).
The collection includes recreations of Windows 3.1, Windows 95, Windows 98, Windows 2000, Windows XP Luna, Olive and Silver, CDE, Solaris CDE, Mac OS 9, Apple System 6/7, OS/2 Warp 4, AmigaOS 1.3 and 2.0, BeOS R5, NeXTSTEP, DESQview/X, QNX Photon, and GEM / Atari TOS. There are also original designs including the neon-soaked Synthwave / NEON OS 1984 theme and additional experimental styles.
Because the themes are built primarily from FireMonkey style objects rather than bitmap skins, the bevels, borders, title bars, buttons, scrollbars, menus, and other UI elements remain crisp at different DPI settings. The style files are also plain, editable FMX resources, making the visual definitions easy to inspect and customize.
The project goes beyond simply reskinning controls. It includes a complete FireMonkey retro desktop and window manager through FMX.RetroWindows, with draggable and resizable windows, desktop icons, activation and z-order management, minimizing, maximizing, taskbars, menu bars, docks, and operating-system-specific window behavior. Switching the active style can transform not only the controls but the entire desktop shell.
That means a Delphi application can behave like a Windows 95 desktop, switch to the striped chrome of Mac OS 9, become an Amiga Workbench-style environment, reproduce the yellow-tab windows of BeOS, or move into the grayscale world of NeXTSTEP; all while remaining a native FireMonkey application for Windows, Linux and macOS.
