Hi, I backported lastest Iceberg version to Pharo 6.1 to allow people to benefit for latest changes. This version has an important amount of tweak and fixes, but most important is the inclusion of tonel file format (this is default for Pharo 7.0, optional for Pharo 6.1) and introduces a file-per-class format. The advantages of this format has everything to do with the speed of access (is easier to reconstruct a package like) and the space on disk (methods are usually small but minimum space in disk is usually 4k so we waste a lot of space). Is also a better format for SSD disks. To backport Iceberg 0.6.2 I also needed to backport latest version of Metacello, so Pharo 6.1 and Pharo7+ users now also have the latest version of it available :) cheers! Esteban