SplitBrowser is a DONATEWARE that will allows you to display multiple HTML pages on single window. You can customize the size of each Frame and display window into full screen mode.
Step By Step
Launch SplitBrowser,
By default, a new document is created with four same URL views,
You can change each URL view by selecting 'Edit' item from 'Site' menu,
Fill the various fields and save your document,
Choose 'Preference' to customize SplitBrowser.