This package (ab)uses the inline enumeration capabilities of
enumitem to add a "displayed" enumeration mode, triggered by
adding 'gathered' to the key-value option list of the enumerate
environment. The end result is similar to a regular enumerate
environment wrapped in a multicols environment, with the
following advantages: Gathered enumerate can pack items
depending on their actual width rather than a fixed, constant
number per line. Gathered enumeration fills items in a
line-major order (instead of column-major order), which my
students found less confusing. YMMV. The package depends on
enumitem, expl3, and xparse.