Complex sentence: The AZARDI 17 Desktop Reader was released on 31 December 2012 with full support for the IDPF Fixed Layout specification, but adds new features such as sliding fixed-layout viewports, asymmetrical page layouts, plus horizontal and vertical page spreads.
Split into simpler sentences: The AZARDI 17 Desktop Reader was released on 31 December 2012. It now supports the IDPF Fixed Layout specification, but adds new features such as sliding fixed-layout viewports, asymmetrical page layouts, plus horizontal and vertical page spreads.