Holy Bonus! It's: TwoUp

TwoUp
Mac Solution: TwoUp. The mac solution is a handy-dandy application called TwoUp. The program is slightly more limited than MaxTo for PC but it is still a little gem for those that hate it when one window dominates the entire screen. Here is a screen shot followed by info from their site:

In Short TwoUp allows you to quickly position a window to fill exactly half the screen (splitscreen) via the status menu bar or configurable shortcuts (hotkeys). Similar to "tiled windows" functionality available on other operating systems.

Using TwoUp TwoUp consists of four actions which can be performed on the frontmost application window:

• Left (move and resize window to fill the left half of the screen)
• Right (move and resize window to fill the right half of the screen)
• Up (move and resize window to fill the top half of the screen)
• Down (move and resize window to fill the bottom half of the screen)

These actions can be triggered via the TwoUp menu in the Mac menu bar or via system wide shortcuts. The default shortcuts can be triggered by holding the Control+Option+Command keys while pressing an Arrow key to indicate the direction you wish the window to go. The shortcut keys can be customized in the TwoUp Preferences.

Check out TwoUp, Download Here.