At its Build developer conference last year, Microsoft announced four "bridges" for bringing applications into the Windows Store. Three of these—for porting Web (codenamed "Westminster"), Win32 ("Centennial"), and iOS ("Islandwood") applications to Windows—are still around, but the company today confirmed that the fourth bridge, Astoria, intended for bringing Android apps to Windows, is no longer in development.
Early builds of Windows 10 Mobile included a version of Astoria, and this essentially did exactly what it was supposed to: it enabled Android apps to run on Windows phones. But last November the Android layer was quietly removed, with Microsoft saying that it was "not ready yet."
Today's announcement suggests that it's never going to be ready. The company writes, rather peculiarly, that choosing between Astoria and Islandwood "could be confusing" and that having two systems for porting non-Windows applications was "unnecessary." Accordingly, Islandwood is the only bridge, and Astoria is being abandoned.