Limba provides developers with a way to easily create software bundles for their applications which run on multiple Linux distributions. It provides atomic upgrades of software, simultaneous installation of multiple software versions and a simple way to obtain and upgrade software.
Limba is based on ideas of Glick2 and Listaller, and uses modern Linux kernel features to allow applications to share libraries and other components, reducing the amount of duplicate software components running on a Linux system.
It heavily uses AppStream metadata.
You can read the initial announcement of Limba here.