Microsoft Corp. has said it will offer a Web-based version of its popular Office software for free, as the software giant looks to battle free Web-based software from Google Inc. and increased competition from open-source products. The software giant has said that Office Web applications would be available through Windows Live, where more than 400 million consumers will get access to the Office Web applications for free. The company has also said it would cut the number of Office editions to five from eight.