LibreOffice was developed by a group of rogue developers from the OpenOffice.org project. They objected to recent attempts to implement some fees on OO, and vowed to keep LibreOffice (LO) completely free. As with all Open Source projects, donations are appreciated.
I've read a bit about the differences and similarities between MSO, OO and LO. It would seem the major differences would be the following:
- LibreOffice does not come with Java, as does OpenOffice, though it is necessary to run LO. It would be hard to imagine you don't already have Java installed on your computer.
- LibreOffice supports Microsoft Works and Wordperfect file types. If you used Works for a long time, then found your new computer didn't come with Works, you either had to buy Works or live without access to your old documents.
- Neither LibreOffice nor OpenOffice include an application similar to Outlook. This is commonly the reason people are still buying Microsoft Office. There are a few alternatives such as Google Calendar, but nothing does it all like Outlook and many businesses are still tied to it.
Detailed article comparing the suites