WeBWorK 2.20 has now been released.
See https://wiki.openwebwork.org/wiki/Release_notes_for_WeBWorK_2.20 for a list of features, upgrades and bug fixes.
Instructions for upgrading your existing server can be found at https://wiki.openwebwork.org/wiki/Release_notes_for_WeBWorK_2.20#Upgrade_Instructions.
Instructions for setting up a new installation can be found at https://wiki.openwebwork.org/wiki/Installation_Manual_for_2.20_on_Ubuntu.