One of the first M6 builds, this compile of 4030 shows the striking red wallpaper introduced for this milestone.
Very little has changed since the publicly leaked 4029 MAIN build, however it is currently the earliest build I've seen to feature the "3D View" menu option, even though it's quite unusable and doesn't draw icons. The old stalwarts Carousel and Panorama can be enabled, similar to later builds.
I haven't shown much in the way of M6 builds so far, mainly because they mostly look the exact same, but hopefully I'll eventually document 4030.main, 4031.main, 4031.Lab06, 4032.Lab06 and some of the SKUs of 4038.main for the collectors. All throughout M6 the Aero Glass style was hidden and hackable into submission, but it wasn't until 4039 that it became easily enable-able, and that continued early on into M7 as can be seen in 4040 and 4042.