We just merged an oft-requested feature in Editor 2 - the ability to edit two resources side-by-side. Simply right-click on an editor tab and choose Move to Other Tab Pane from the context menu to move the selected tab to a new pane beside the existing tab pane. You can now move tabs between the two tab panes using the same command. To return to a single all-encompassing tab pane, simply select Join Tab Panes from the same context menu. There is also a Swap With Other Tab Pane command if you prefer to switch the left-right order of the two visible tabs.
Please try it out and let us know if you encounter any issues!