New release R6.
This one brings mainly one thing: Compatibility with AGS 2.60 and up.

There are a few glitches that occur in older games though. They are the same as running the games with the 3.1.1 Windows engine and are most likely caused by bug fixes and subtle data format changes.
A strange bug is that drawing order calculations in 2.x seem to be done differently than in the current version. This is very much noticable in the intro to Garfield. Also in Ben Jordan 7, after the Ben walks into his room in the intro he is drawn on top of the door while it is closed instead of behind it. Both Ben and the door have the same baseline value that is calculated from their y-position. Therefore is is probable that the order in which objects and characters are added to the "things to draw" list is inverted in 3.x compared to 2.x.
Also in the Ben Jordan games, especially in the deluxe versions: Ben often faces the wrong direction when entering a room. There is a script call to FaceLocation just before the room changes that turns the character around. It looks like that call is supposed to happen after the room change though. Very puzzling.
On the technical side, what was done to achieve the compatibility is adding the legacy formats to the loading function and writing a parser for the old dialog scripts. You can check that in the commit log.
As always, the download and source links are in the opening post.