The functionality and design choices for window management are based on the computer technology of the 1980's. In 1980's, a compact window manager was necessary for fast response due to limited processing power and memory capacities of computer systems.
Overlapping windows came as a solution to the small-screen problem by
allowing more windows to be open simultaneously. While the typical
display resolution was 
in the 1980's, resolutions
such as 
are common these days, which is roughly
four times larger.
The rationale behind independence of window operations was two-fold. First, each window was typically seen as a visual representation of a single independent application. This was in part due to the tendency to see multiple windows as multiple full-screen visual display units, requiring no interaction with other windows. Secondly, due to the limited processing power and lack of sophisticated event processing models, the concurrency of the system was low, limiting interaction involving multiple windows considerably.
Operations on overlapping windows required modest graphics power to copy and move blocks of pixels. Animations that demand more graphics power were used rarely to give feedback to the user on window operations.
Today, the tendency is towards information-centric interaction, where applications fade into the background. Users focus on pieces of information not on applications. They desire to work simultaneously with many documents, designs, diagrams, source-code pieces etc. In the information-centric approach information is scattered into multiple windows with high dependencies. Today, advanced applications provide users multiple windows, where users can work with many pieces of information. The information-centric approach gives users more flexibility in terms of organization and manipulation of multiple pieces of information.
However, advances in the computer technology both in hardware and software with increased user expectations are making the design principles of the independent overlapping windows approach obsolete and problematic in performing some tasks. In the following sections, problems regarding organization, access and manipulation of information are discussed in detail with supportive results from the user observations that I conducted.