Based on Openoffice.com technology, IBM’s Office Suite can be a nice alternative for MS Office. Although it’s based on openoffice.com technology it’s not an open source but just a freeware, which never comes in way when trying this Office Suite. The latest version has many new features like support for Microsoft Office 2007 files,password protection for spreadsheets, and envelope printing. The toolbar and menu are more accessible and usable, too. Mail merge, drop and drag file access, and Arial default font seem like small changes but they dramatically increase the usability of the suite. Lotus Symphony uses Open Document format by default for saving files.
A major draw back is that it consumes a lot of memory and could slowdown your rest of running .programs.