[development] module duplication in Drupal contrib

[Nancy Wichmann]

> "Modules that duplicate functionality available from an existing module
are damaging to the Drupal project."

> Please support or refute that statement...

Support: Crell has a point about making the wheel better. If combining
modules can accomplish this it should definitely be considered.

Refute: Almost all blanket statements such as this are wrong at some point.
Because "function xyz" is available from both the "abc" and "def" modules
doesn't necessarily mean they should be combined.  There are undoubtedly
other functions in those modules and it may be that an adopter of one of
them simply does not need (or want) the additional functions in the other.
It is also quite possible that the display format from "abc" is more to
his/her preference than that of "def."

I've also seen users complain that "def" required "ghi" and they only want
to install, and maintain, one module.  In a sense, such an inter-module
dependency has thus "damaged" Drupal for that user.

I personally have been told (not asked or recommended) to merge one of the
modules I maintain with another. However the two modules really have
different audiences even though the descriptions are similar. Further, the
design of the two was so different that it would really have caused a
complete rewrite of one or both of them, likely with a loss of function.
Perhaps a statement comparing and contrasting the solutions offered would
have been a more appropriate demand.

Nancy E. Wichmann, PMP