Logos 4.2a Beta 3 (v4.21.4.8572) is available for testing.
To upgrade from a shipping version, such as 4.0b SR-2, enter "set update channel to beta" command to begin download, or "update now" if you've already switched to the beta channel. To install from scratch, via download, click here: http://downloads.logos.com/LBS4/LBS4MacInstallerBeta/Logos4Mac.dmg.
For Release Notes, see http://wiki.logos.com/Logos_4.2a_Beta_3.