Office Tabs is fully free for personal users. No time limitation, No features limitation.
Tabbed Editing and Managing for Microsoft Office 2010 64-bit. Unlike web browsers -- Internet Explorer 8, Firefox or Chrome, Microsoft Office does not use a single window to hold multiple files for viewing and editing. Office Tabs brings this feature into MS Office, and adds tabbed user interface into Microsoft Office 2010 64-bit.

Office Tabs is completely free for home use. Users can free distribute, install, copy, backup, or upload the software to computers or websites.

It works with all editions of MS Office 2010 64-bit: Enterprise, Ultimate, Professional Plus, Professional, Standard, Home and Business (Small Business), Home and Student...

Office Tabs includes Office Tabs for Word, Office Tabs for Excel and Office Tabs for PowerPoint. Office tabs will bring you many useful features:

(1) Open, read, edit and manage multiple Office documents in a tabbed window,
(2) Without filling your desktop with new, unorganized Office windows.
(3) Save all documents in one click! Easy determine which file has been changed, which has been saved: Office Tab will mark these modified documents or workbooks with an asterisk (*) in their names to indicate the modified documents or workbooks (except in PowerPoint).
(4) You can close a tab by double-clicking the left button on it.
(5) You can close a tab by clicking the middle mouse button once.
(6) Close All: close all files in the tabbed windows (a confirmation dialog box will appear when you choose to close all files).
(7) Close others: close other files (exclude current file) in the tabbed windows.
(8) Quickly Rename. This function is different from "save as", once "rename" is applied, the document file under the original name does not exist anymore.