Microsoft Corp didn’t wait for Sun Microsystems Inc’s SunSelect unit actually to announce its Windows-under-Unix Wabi system before taking retaliatory action (CI No 2,1620. It has now formally signed an agreement that enables the High Wycombe, Buckinghamshire and Mountain View, California-based Insignia Solutions Ltd to modify Windows source code at the application programming interface to improve the performance of its SoftPC Windows under Unix package. Along with the source code, Insignia gets associated intellectual property including the Windows user interface, Windows Application Programming Interfaces, and rights to use the Windows trademark and logo. The agreement will also enable Insignia to improve the Windows on Apple Computer Inc Macintosh version of its emulation software. Microsoft says that it is developing tools which will enable C and C++ developers building Windows-based applications to target the Macintosh. The tools will give developers access to Macintosh System 7 programming interfaces, and will include a layer that implements Windows APIs on the System 7 operating system. Access to Microsoft’s technology should make SoftPC run MS-DOS and Windows programs at near native performance by the end of the year. Insignia has already taken a 10% stake in Bridgefield, Connecticut-based Bristol Technology Inc, capping a deal for the two firms to develop and combine products that will enable Windows applications to run on desktop Unix systems. The project is focused on the speed at which programs run. Bristol’s source-level Windows-under-Unix API, Wind/U, will be made to run Windows applications. Insignia’s SoftPC runs 16-bit binary MS-DOS and Windows programs under Unix. No more is known at present because plans are still changing, but Bill Gates’s threats to make life miserable for Wabi by bringing out competing products of his own are believed to involve Bristol and a Microsoft licence to Wind/U. Insignia’s SoftPC – which is being used to run 16-bit MS-DOS and Windows applications under Windows NT – will be the other binary rock that Microsoft throws at Wabi. With Windows source code, Insignia would not face the problems that Sun faces keeping up with Windows development. Microsoft has also licensed Windows source code to companies such as Citrix Systems Inc, which will deliver a multi-user version of Windows NT.