Today the first release candidate for LibreOffice 4.0.0 has been made available for download for evaluation, quality assurance (QA) testing and the like.
The developers do nevertheless stress that they do not recommend the use of LibreOffice pre-release builds for “mission-critical” purposes. Information about QA testing can be found on the LibreOffice QA testers page.
The developers also suggest reading the release notes.
If you’re interested in even more bleeding-edge binaries of LibreOffice’s current development, check out the nightly builds. However, these are potentially even less suitable for productive work, provided by individual contributors and not QA-approved in any way. Caveat emptor.
To download LibreOffice 4.0.0.0 RC1 visit the pre-release page. To download the right package for your particular system, you’ll need to select the right package from the two dropdown lists on the page; there is an automatic detection system to help, but this might not work in all cases. The release candidate is available for GNU/Linux (rpm and deb-based package management systems), Mac OS X (both Intel and PowerPC versions) and Windows.