Systems and methods are provided for building a complex document. A system can include a memory for storing computer executable instructions and a processing unit for accessing the memory and executing the computer executable instructions. The computer executable instructions can include a graphical user interface engine to display a target complex document browser and a plurality of source complex document browsers, such that elements and containers contained within a complex document displayed by each of the source complex document browsers are copyable into the target complex document browser in response to user input information to build a new complex document.