For commercial support around LibreOffice see our list of certified partners.
Selected: LibreOffice Windows, version 4.3.1, English (US)
This version of LibreOffice is prepared with care and presented with pride by the LibreOffice community. PLEASE NOTE that, since this is the very second version in the series, make sure to read the release notes (under "Handy resources").
Download the SDK for developing extensions and external tools.
LibreOffice is an open source project and you can therefore download the source code to build your own installer.