There are many free and open source alternatives of Microsoft Office including LibreOffice and Calligra Suite. The Calligra team has announced the release of version 2.7 of the Calligra Suite, Calligra active and the Calligra Office Engine.
Inge Wallin says, “The version number of this release is actually 2.7.1, not 2.7.0 because a serious problem was found after the tagging of 2.7.0. Due to the release process, the team had to withdraw 2.7.0 and instead release 2.7.1 as the first stable version of the 2.7 series.”
One application of the suite that sets it apart from the rest is Author which is targeted at writers to assist them in writing books. The new version has new support for EPUB3: mathematical formulas and multimedia contents are now exported to ebooks using the EPUB format. There is also new support for book covers using images.
Calligra is available for GNU/Linux and Windows. You can download and try it from this link.