The APT (Advanced Packaging Tool) for Debian systems upgraded, and certainly true for over a decade, but there are a couple of new projects that believe they could make at least some of that work better.
Cupto One is written in Perl and developed with three main objectives: to avoid some errors in the design of APT, and introduce some useful features to the basic code extensible and readable. Cupto already available in version 1.0.0 ~ beta1 in the repositories of Debian “unstable” and uses the same infrastructure APT as index files, and cache configuration.
APT2 is written in Vala and the new language is primarily a library to work with the Debian repositories and packages. APT2 only requires GLib, Gee and libarchive, or about 2 MB of space, which can make it especially attractive in environments with storage considerations, such as embedded.
It is noteworthy that both are part of APT reimplementations written from scratch by their respective authors.