Complex sentence: On August 9,2012, it emerged that Microsoft was planning to use the term "Windows 8" to replace Metro in consumer marketing materials, with "Modern UI" being intended for developers who plan to build software based on Microsoft's new design principles.
Split into simpler sentences: On August 9,2012, it emerged that Microsoft was planning to use the term "Windows 8" to replace Metro in consumer marketing materials. The "Modern UI" term appears to be intended for developers who plan to build software based on Microsoft's new design principles.